SEGMENT INFORMATION The accounting policies used to prepare the segment reporting data for the Companys three reportable business segments are the same as those described in the Summary of Significant Accounting Policies in note 1. Except as described below for certain legal entities, the Company allocates its invested assets and the related net investment income to its reportable business segments. Pre-tax net investment income is allocated based upon an investable funds concept, which takes into account liabilities (net of non-invested assets) and appropriate capital considerations for each segment. For investable funds, a benchmark investment yield is developed that reflects the estimated duration of the loss reserves future cash flows, the interest rate environment at the time the losses were incurred and A+ rated corporate debt instrument yields. For capital, a benchmark investment yield is developed that reflects the average yield on the total investment portfolio. The benchmark investment yields are applied to each segments investable funds and capital, respectively, to produce a total notional investment income by segment. The Companys actual net investment income is allocated to each segment in proportion to the respective segments notional investment income to total notional investment income. There are certain legal entities within the Company that are dedicated to specific reportable business segments. The invested assets and related net investment income from these legal entities are reported in the applicable business segment and are not allocated among the other business segments. The cost of the Companys catastrophe treaty program is included in the Companys ceded premiums and is allocated among reportable business segments based on an estimate of actual market reinsurance pricing using expected losses calculated by the Companys catastrophe model, adjusted for any experience adjustments. The following tables summarize the components of the Companys revenues, income, net written premiums and total assets by reportable business segments. (for the year ended December 31, in millions) Business Insurance Bond &amp; Specialty Insurance Personal Insurance Total Reportable Segments 2019 Premiums $ 15,300 $ 2,565 $ 10,407 $ 28,272 Net investment income 1,816 233 419 2,468 Fee income 437  22 459 Other revenues 155 26 87 268 Total segment revenues (1) $ 17,708 $ 2,824 $ 10,935 $ 31,467 Amortization and depreciation $ 3,037 $ 533 $ 1,787 $ 5,357 Income tax expense 223 151 195 569 Segment income (1) 1,392 618 824 2,834 2018 Premiums $ 14,722 $ 2,420 $ 9,917 $ 27,059 Net investment income 1,833 233 408 2,474 Fee income 412  20 432 Other revenues 112 23 66 201 Total segment revenues (1) $ 17,079 $ 2,676 $ 10,411 $ 30,166 Amortization and depreciation $ 2,943 $ 515 $ 1,719 $ 5,177 Income tax expense 259 198 42 499 Segment income (1) 1,638 793 297 2,728 2017 Premiums $ 14,146 $ 2,307 $ 9,230 $ 25,683 Net investment income 1,786 228 383 2,397 Fee income 430  17 447 Other revenues 69 24 60 153 Total segment revenues (1) $ 16,431 $ 2,559 $ 9,690 $ 28,680 Amortization and depreciation $ 2,852 $ 493 $ 1,627 $ 4,972 Income tax expense (benefit) 448 208 (44 ) 612 Segment income (1) 1,613 556 128 2,297 _________________________________________ (1) Segment revenues for reportable business segments exclude net realized investment gains. Segment income for reportable business segments equals net income excluding the after-tax impact of net realized investment gains and, in 2017, the impact of the Tax Cuts and Jobs Act of 2017 at enactment. Net written premiums by market were as follows: (for the year ended December 31, in millions) 2019 2018 2017 Business Insurance: Domestic: Select Accounts $ 2,911 $ 2,828 $ 2,800 Middle Market 8,630 8,214 7,756 National Accounts 1,051 1,025 1,010 National Property and Other 1,965 1,805 1,691 Total Domestic 14,557 13,872 13,257 International 1,072 1,084 1,013 Total Business Insurance 15,629 14,956 14,270 Bond &amp; Specialty Insurance: Domestic: Management Liability 1,605 1,455 1,367 Surety 866 835 793 Total Domestic 2,471 2,290 2,160 International 268 238 199 Total Bond &amp; Specialty Insurance 2,739 2,528 2,359 Personal Insurance: Domestic: Agency: Automobile 5,124 4,972 4,646 Homeowners and Other 4,540 4,148 3,933 Total Agency 9,664 9,120 8,579 Direct-to-Consumer 412 396 361 Total Domestic 10,076 9,516 8,940 International 707 708 650 Total Personal Insurance 10,783 10,224 9,590 Total consolidated net written premiums $ 29,151 $ 27,708 $ 26,219 Business Segment Reconciliations (for the year ended December 31, in millions) 2019 2018 2017 Revenue reconciliation Earned premiums Business Insurance: Domestic: Workers compensation $ 3,829 $ 3,899 $ 3,962 Commercial automobile 2,632 2,388 2,132 Commercial property 1,937 1,828 1,775 General liability 2,342 2,181 2,047 Commercial multi-peril 3,453 3,333 3,198 Other 40 28 29 Total Domestic 14,233 13,657 13,143 International 1,067 1,065 1,003 Total Business Insurance 15,300 14,722 14,146 Bond &amp; Specialty Insurance: Domestic: Fidelity and surety 1,036 1,017 977 General liability 1,082 1,004 962 Other 216 195 187 Total Domestic 2,334 2,216 2,126 International 231 204 181 Total Bond &amp; Specialty Insurance 2,565 2,420 2,307 Personal Insurance: Domestic Automobile 5,311 5,097 4,655 Homeowners and Other 4,393 4,135 3,943 Total Domestic 9,704 9,232 8,598 International 703 685 632 Total Personal Insurance 10,407 9,917 9,230 Total earned premiums 28,272 27,059 25,683 Net investment income 2,468 2,474 2,397 Fee income 459 432 447 Other revenues 268 201 153 Total segment revenues 31,467 30,166 28,680 Other revenues 1 2 6 Net realized investment gains 113 114 216 Total revenues $ 31,581 $ 30,282 $ 28,902 Income reconciliation, net of tax Total segment income $ 2,834 $ 2,728 $ 2,297 Interest Expense and Other (1) (297 ) (298 ) (254 ) Core income 2,537 2,430 2,043 Net realized investment gains 85 93 142 Impact of Tax Cuts and Jobs Act of 2017 at enactment   (129 ) Net income $ 2,622 $ 2,523 $ 2,056 ________________________________________ (1) The primary component of Interest Expense and Other was after-tax interest expense of $272 million , $278 million and $240 million in 2019 , 2018 and 2017 , respectively. (at December 31, in millions) 2019 2018 Asset reconciliation: Business Insurance $ 83,896 $ 78,965 Bond &amp; Specialty Insurance 8,599 8,693 Personal Insurance 17,015 15,943 Total assets for reportable segments 109,510 103,601 Other assets (1) 612 632 Total consolidated assets $ 110,122 $ 104,233 ___________________________________________ (1) The primary components of other assets at both December 31, 2019 and 2018, were accrued over-funded benefit plan assets related to the Company's qualified domestic pension plan and other intangible assets. Enterprise-Wide Disclosures The Company does not have revenue from transactions with a single customer amounting to 10 percent or more of its revenues. The following table presents revenues of the Companys operations based on location: (for the year ended December 31, in millions) 2019 2018 2017 U.S. $ 29,638 $ 28,418 $ 27,253 Non-U.S.: Canada 1,371 1,293 1,232 Other Non-U.S. 572 571 417 Total Non-U.S. 1,943 1,864 1,649 Total revenues $ 31,581 $ 30,282 $ 28,902