SEGMENT REPORTING The Companys reportable segments are defined as follows: (1) Property, which is comprised of catastrophe and other property reinsurance and insurance written on behalf of the Companys operating subsidiaries and certain joint ventures managed by the Companys ventures unit, and (2) Casualty and Specialty, which is comprised of casualty and specialty reinsurance and insurance written on behalf of the Companys operating subsidiaries and certain joint ventures managed by the Companys ventures unit. In addition to its reportable segments, the Company has an Other category, which primarily includes its strategic investments, investments unit, corporate expenses, capital servicing costs, noncontrolling interests and the remnants of its former Bermuda-based insurance operations. The Companys Property segment is managed by the Chief Underwriting Officer - Property and the Casualty and Specialty segment is managed by the Chief Underwriting Officer - Casualty and Specialty, each of whom operate under the direction of the Companys Group Chief Underwriting Officer, who in turn reports to the Companys President and Chief Executive Officer. The Company does not manage its assets by segment; accordingly, net investment income and total assets are not allocated to the segments. A summary of the significant components of the Companys revenues and expenses by segment is as follows: Year ended December 31, 2018 Property Casualty and Specialty Other Total Gross premiums written $ 1,760,926 $ 1,549,501 $  $ 3,310,427 Net premiums written $ 1,055,188 $ 1,076,714 $  $ 2,131,902 Net premiums earned $ 1,050,831 $ 925,298 $  $ 1,976,129 Net claims and claim expenses incurred 497,895 622,320 (197 ) 1,120,018 Acquisition expenses 177,912 255,079 (2 ) 432,989 Operational expenses 112,954 64,883 430 178,267 Underwriting income (loss) $ 262,070 $ (16,984 ) $ (231 ) 244,855 Net investment income 261,866 261,866 Net foreign exchange losses (12,428 ) (12,428 ) Equity in earnings of other ventures 18,474 18,474 Other income 5,969 5,969 Net realized and unrealized losses on investments (175,069 ) (175,069 ) Corporate expenses (33,983 ) (33,983 ) Interest expense (47,069 ) (47,069 ) Income before taxes and redeemable noncontrolling interests 262,615 Income tax benefit 6,302 6,302 Net income attributable to redeemable noncontrolling interests (41,553 ) (41,553 ) Dividends on preference shares (30,088 ) (30,088 ) Net income available to RenaissanceRe common shareholders $ 197,276 Net claims and claim expenses incurred  current accident year $ 719,185 $ 671,582 $  $ 1,390,767 Net claims and claim expenses incurred  prior accident years (221,290 ) (49,262 ) (197 ) (270,749 ) Net claims and claim expenses incurred  total $ 497,895 $ 622,320 $ (197 ) $ 1,120,018 Net claims and claim expense ratio  current accident year 68.4 % 72.6 % 70.4 % Net claims and claim expense ratio  prior accident years (21.0 )% (5.3 )% (13.7 )% Net claims and claim expense ratio  calendar year 47.4 % 67.3 % 56.7 % Underwriting expense ratio 27.7 % 34.5 % 30.9 % Combined ratio 75.1 % 101.8 % 87.6 % Year ended December 31, 2017 Property Casualty and Specialty Other Total Gross premiums written $ 1,440,437 $ 1,357,110 $ (7 ) $ 2,797,540 Net premiums written $ 978,014 $ 893,307 $ 4 $ 1,871,325 Net premiums earned $ 931,070 $ 786,501 $ 4 $ 1,717,575 Net claims and claim expenses incurred 1,297,985 565,026 (1,583 ) 1,861,428 Acquisition expenses 113,816 233,077 (1 ) 346,892 Operational expenses 94,194 66,548 36 160,778 Underwriting (loss) income $ (574,925 ) $ (78,150 ) $ 1,552 (651,523 ) Net investment income 222,209 222,209 Net foreign exchange gains 10,628 10,628 Equity in earnings of other ventures 8,030 8,030 Other income 9,415 9,415 Net realized and unrealized gains on investments 135,822 135,822 Corporate expenses (18,572 ) (18,572 ) Interest expense (44,193 ) (44,193 ) Loss before taxes and noncontrolling interests (328,184 ) Income tax expense (26,487 ) (26,487 ) Net loss attributable to noncontrolling interests 132,282 132,282 Dividends on preference shares (22,381 ) (22,381 ) Net loss attributable to RenaissanceRe common shareholders $ (244,770 ) Net claims and claim expenses incurred  current accident year $ 1,343,581 $ 558,843 $  $ 1,902,424 Net claims and claim expenses incurred  prior accident years (45,596 ) 6,183 (1,583 ) (40,996 ) Net claims and claim expenses incurred  total $ 1,297,985 $ 565,026 $ (1,583 ) $ 1,861,428 Net claims and claim expense ratio  current accident year 144.3 % 71.1 % 110.8 % Net claims and claim expense ratio  prior accident years (4.9 )% 0.7 % (2.4 )% Net claims and claim expense ratio  calendar year 139.4 % 71.8 % 108.4 % Underwriting expense ratio 22.3 % 38.1 % 29.5 % Combined ratio 161.7 % 109.9 % 137.9 % Year ended December 31, 2016 Property Casualty and Specialty Other Total Gross premiums written $ 1,111,263 $ 1,263,313 $  $ 2,374,576 Net premiums written $ 725,321 $ 809,848 $ 143 $ 1,535,312 Net premiums earned $ 720,951 $ 682,337 $ 142 $ 1,403,430 Net claims and claim expenses incurred 151,545 380,396 (1,110 ) 530,831 Acquisition expenses 97,594 191,729  289,323 Operational expenses 108,642 88,984 123 197,749 Underwriting income $ 363,170 $ 21,228 $ 1,129 385,527 Net investment income 181,726 181,726 Net foreign exchange losses (13,788 ) (13,788 ) Equity in earnings of other ventures 963 963 Other income 14,178 14,178 Net realized and unrealized gains on investments 141,328 141,328 Corporate expenses (37,402 ) (37,402 ) Interest expense (42,144 ) (42,144 ) Income before taxes and noncontrolling interests 630,388 Income tax expense (340 ) (340 ) Net income attributable to noncontrolling interests (127,086 ) (127,086 ) Dividends on preference shares (22,381 ) (22,381 ) Net income available to RenaissanceRe common shareholders $ 480,581 Net claims and claim expenses incurred  current accident year $ 256,421 $ 438,536 $  $ 694,957 Net claims and claim expenses incurred  prior accident years (104,876 ) (58,140 ) (1,110 ) (164,126 ) Net claims and claim expenses incurred  total $ 151,545 $ 380,396 $ (1,110 ) $ 530,831 Net claims and claim expense ratio  current accident year 35.6 % 64.3 % 49.5 % Net claims and claim expense ratio  prior accident years (14.6 )% (8.6 )% (11.7 )% Net claims and claim expense ratio  calendar year 21.0 % 55.7 % 37.8 % Underwriting expense ratio 28.6 % 41.2 % 34.7 % Combined ratio 49.6 % 96.9 % 72.5 % The following is a summary of the Companys gross premiums written allocated to the territory of coverage exposure: Year ended December 31, 2018 2017 2016 Property U.S. and Caribbean $ 978,063 $ 954,269 $ 743,226 Worldwide 464,311 305,915 210,168 Europe 144,857 49,486 37,611 Japan 71,601 49,821 44,536 Worldwide (excluding U.S.) (1) 66,872 48,182 55,043 Australia and New Zealand 19,273 14,151 13,729 Other 15,949 18,613 6,950 Total Property 1,760,926 1,440,437 1,111,263 Casualty and Specialty Worldwide 776,976 686,253 581,972 U.S. and Caribbean 667,125 622,757 646,381 Worldwide (excluding U.S.) (1) 31,734 10,104 13,840 Europe 15,296 9,752 5,541 Australia and New Zealand 3,667 4,141 5,073 Other 54,703 24,103 10,506 Total Casualty and Specialty 1,549,501 1,357,110 1,263,313 Other category  (7 )  Total gross premiums written $ 3,310,427 $ 2,797,540 $ 2,374,576 (1) The category Worldwide (excluding U.S.) consists of contracts that cover more than one geographic region (other than the U.S.).