18. Segment Reporting As of September 30, 2020, we evaluated our business and made resource allocations based on six reportable business segments: medical office buildings, hospitals, skilled nursing facilities, senior housing, senior housing  RIDEA and integrated senior health campuses. Our medical office buildings are typically leased to multiple tenants under separate leases, thus requiring active management and responsibility for many of the associated operating expenses (much of which are, or can effectively be, passed through to the tenants). Our hospital investments are primarily single-tenant properties for which we lease the facilities to unaffiliated tenants under triple-net and generally master leases that transfer the obligation for all facility operating costs (including maintenance, repairs, taxes, insurance and capital expenditures) to the tenant. Our skilled nursing and senior housing facilities are similarly structured to our hospital investments. In addition, our senior housing segment includes our debt security investment. Our senior housing  RIDEA properties include senior housing facilities that are owned and operated utilizing a RIDEA structure. Our integrated senior health campuses include a range of assisted living, memory care, independent living, skilled nursing services and certain ancillary businesses that are owned and operated utilizing a RIDEA structure. We evaluate performance based upon segment net operating income. We define segment net operating income as total revenues and grant income, less property operating expenses and rental expenses, which excludes depreciation and amortization, general and administrative expenses, acquisition related expenses, interest expense, gain or loss in fair value of derivative financial instruments, gain or loss on dispositions of real estate investments, impairment of real estate investments, foreign currency gain or loss, other income, income or loss from unconsolidated entities and income tax benefit or expense for each segment. We believe that net income (loss), as defined by GAAP, is the most appropriate earnings measurement. However, we believe that segment net operating income serves as an appropriate supplemental performance measure to net income (loss) because it allows investors and our management to measure unlevered property-level operating results and to compare our operating results to the operating results of other real estate companies and between periods on a consistent basis. Interest expense, depreciation and amortization and other expenses not attributable to individual properties are not allocated to individual segments for purposes of assessing segment performance. Non-segment assets primarily consist of corporate assets including cash and cash equivalents, other receivables, deferred financing costs and other assets not attributable to individual properties. Summary information for the reportable segments during the three and nine months ended September 30, 2020 and 2019 was as follows: Integrated Senior Health Campuses Senior Housing  RIDEA Medical Office Buildings Senior Housing Skilled Nursing Facilities Hospitals Three Months Ended September 30, 2020 Revenues and grant income: Resident fees and services $ 242,714,000 $ 21,217,000 $  $  $  $  $ 263,931,000 Real estate revenue   19,675,000 4,245,000 3,676,000 2,737,000 30,333,000 Grant income 740,000      740,000 Total revenues and grant income 243,454,000 21,217,000 19,675,000 4,245,000 3,676,000 2,737,000 295,004,000 Expenses: Property operating expenses 225,199,000 15,790,000     240,989,000 Rental expenses   7,304,000 9,000 369,000 113,000 7,795,000 Segment net operating income $ 18,255,000 $ 5,427,000 $ 12,371,000 $ 4,236,000 $ 3,307,000 $ 2,624,000 $ 46,220,000 Expenses: General and administrative $ 6,969,000 Acquisition related expenses 54,000 Depreciation and amortization 24,591,000 Other income (expense): Interest expense: Interest expense (including amortization of deferred financing costs and debt discount/premium) (17,229,000) Gain in fair value of derivative financial instruments 1,763,000 Gain on dispositions of real estate investments 1,037,000 Loss from unconsolidated entities (2,855,000) Foreign currency gain 1,945,000 Other income 203,000 Loss before income taxes (530,000) Income tax expense (150,000) Net loss $ (680,000) Integrated Senior Health Campuses Senior Housing  RIDEA Medical Office Buildings Senior Housing Skilled Nursing Facilities Hospitals Three Months Ended September 30, 2019 Revenues: Resident fees and services $ 257,048,000 $ 16,752,000 $  $  $  $  $ 273,800,000 Real estate revenue   19,890,000 2,601,000 2,672,000 2,799,000 27,962,000 Total revenues 257,048,000 16,752,000 19,890,000 2,601,000 2,672,000 2,799,000 301,762,000 Expenses: Property operating expenses 230,349,000 11,509,000     241,858,000 Rental expenses   8,140,000 553,000 346,000 149,000 9,188,000 Segment net operating income $ 26,699,000 $ 5,243,000 $ 11,750,000 $ 2,048,000 $ 2,326,000 $ 2,650,000 $ 50,716,000 Expenses: General and administrative $ 7,675,000 Acquisition related expenses 4,000 Depreciation and amortization 36,778,000 Other income (expense): Interest expense: Interest expense (including amortization of deferred financing costs, debt discount/premium and loss on debt extinguishment) (21,046,000) Loss in fair value of derivative financial instruments (1,169,000) Loss from unconsolidated entities (766,000) Foreign currency loss (1,464,000) Other income 1,923,000 Loss before income taxes (16,263,000) Income tax expense (840,000) Net loss $ (17,103,000) Integrated Senior Health Campuses Senior Housing  RIDEA Medical Office Buildings Senior Housing Skilled Nursing Facilities Hospitals Nine Months Ended September 30, 2020 Revenues and grant income: Resident fees and services $ 743,340,000 $ 65,134,000 $  $  $  $  $ 808,474,000 Real estate revenue   58,853,000 11,038,000 12,415,000 8,258,000 90,564,000 Grant income 30,730,000      30,730,000 Total revenues and grant income 774,070,000 65,134,000 58,853,000 11,038,000 12,415,000 8,258,000 929,768,000 Expenses: Property operating expenses 683,332,000 47,588,000     730,920,000 Rental expenses   22,536,000 52,000 1,195,000 329,000 24,112,000 Segment net operating income $ 90,738,000 $ 17,546,000 $ 36,317,000 $ 10,986,000 $ 11,220,000 $ 7,929,000 $ 174,736,000 Expenses: General and administrative $ 21,324,000 Acquisition related expenses 307,000 Depreciation and amortization 74,250,000 Other income (expense): Interest expense: Interest expense (including amortization of deferred financing costs and debt discount/premium) (53,415,000) Loss in fair value of derivative financial instruments (5,671,000) Gain on dispositions of real estate investments 1,037,000 Impairment of real estate investments (8,335,000) Loss from unconsolidated entities (3,065,000) Foreign currency loss (1,303,000) Other income 1,279,000 Income before income taxes 9,382,000 Income tax benefit 2,942,000 Net income $ 12,324,000 Integrated Senior Health Campuses Senior Housing  RIDEA Medical Office Buildings Senior Housing Skilled Nursing Facilities Hospitals Nine Months Ended September 30, 2019 Revenues: Resident fees and services $ 764,803,000 $ 49,751,000 $  $  $  $  $ 814,554,000 Real estate revenue   60,548,000 14,184,000 9,998,000 8,467,000 93,197,000 Total revenues 764,803,000 49,751,000 60,548,000 14,184,000 9,998,000 8,467,000 907,751,000 Expenses: Property operating expenses 681,996,000 34,704,000     716,700,000 Rental expenses   23,553,000 776,000 1,076,000 434,000 25,839,000 Segment net operating income $ 82,807,000 $ 15,047,000 $ 36,995,000 $ 13,408,000 $ 8,922,000 $ 8,033,000 $ 165,212,000 Expenses: General and administrative $ 21,104,000 Acquisition related expenses (292,000) Depreciation and amortization 87,149,000 Other income (expense): Interest expense: Interest expense (including amortization of deferred financing costs, debt discount/premium and loss on debt extinguishment) (59,665,000) Loss in fair value of derivative financial instruments (5,846,000) Loss from unconsolidated entities (1,713,000) Foreign currency loss (1,654,000) Other income 2,377,000 Loss before income taxes (9,250,000) Income tax expense (1,150,000) Net loss $ (10,400,000) Total assets by reportable segment as of September 30, 2020 and December 31, 2019 were as follows: September 30, 2020 December 31, 2019 Integrated senior health campuses $ 1,914,639,000 $ 1,791,868,000 Medical office buildings 616,944,000 620,292,000 Senior housing  RIDEA 351,237,000 360,823,000 Senior housing 149,289,000 152,909,000 Skilled nursing facilities 119,366,000 126,606,000 Hospitals 110,545,000 113,737,000 Other 9,169,000 6,054,000 Total assets $ 3,271,189,000 $ 3,172,289,000 As of both September 30, 2020 and December 31, 2019, goodwill of $75,309,000 was allocated to integrated senior health campuses, and no other segments had goodwill. Our portfolio of properties and other investments are located in the United States, Isle of Man and the UK. Revenues and grant income and assets are attributed to the country in which the property is physically located. The following is a summary of geographic information for our operations for the periods presented: Three Months Ended September 30, Nine Months Ended September 30, 2020 2019 2020 2019 Revenues and grant income: United States $ 293,796,000 $ 300,609,000 $ 926,202,000 $ 904,152,000 International 1,208,000 1,153,000 3,566,000 3,599,000 $ 295,004,000 $ 301,762,000 $ 929,768,000 $ 907,751,000 The following is a summary of real estate investments, net by geographic regions as of September 30, 2020 and December 31, 2019: September 30, 2020 December 31, 2019 Real estate investments, net: United States $ 2,278,720,000 $ 2,219,882,000 International 48,222,000 50,539,000 $ 2,326,942,000 $ 2,270,421,000