Schedule of Accumulated Other Comprehensive Income (Loss) [Table Text Block] | Three months ended Three months ended September 30, 2018 September 30, 2017 Before Tax Income Tax Net Before Tax Income Tax Net Accumulated unrealized loss, net, on investments available for sale, beginning of period $ (246,870 ) $ (51,711 ) $ (195,159 ) $ 53,214 $ 18,097 $ 35,117 Other comprehensive (loss) income before reclassification (2,628 ) (557 ) (2,071 ) 23,208 7,890 15,318 Reclassification adjustment for realized investment loss (gains), net, included in realized gains on investments, net 7,648 1,606 6,042 (12,512 ) (4,254 ) (8,258 ) Effect on other comprehensive income 5,020 1,049 3,971 10,696 3,636 7,060 Accumulated unrealized (loss) gains, net, on investments available for sale, end of period $ (241,850 ) $ (50,662 ) $ (191,188 ) $ 63,910 $ 21,733 $ 42,177 Accumulated unrealized gains (loss), net, on interest rate swap, beginning of period $ 30,478 $ 7,311 $ 23,167 $ (5,330 ) $ (1,812 ) $ (3,518 ) Other comprehensive income before reclassification 4,693 986 3,707 1,320 449 871 Effect on other comprehensive gains 4,693 986 3,707 1,320 449 871 Accumulated unrealized income (loss), net, on interest rate swap, end of period $ 35,171 $ 8,297 $ 26,874 $ (4,010 ) $ (1,363 ) $ (2,647 ) Accumulated other comprehensive loss, beginning of period $ (216,392 ) $ (44,400 ) $ (171,992 ) $ 47,884 $ 16,285 $ 31,599 Change in unrealized gains, net, on investments available for sale 5,020 1,049 3,971 10,696 3,636 7,060 Change in unrealized gains, net, on interest rate swap 4,693 986 3,707 1,320 449 871 Effect on other comprehensive income 9,713 2,035 7,678 12,016 4,085 7,931 Accumulated other comprehensive (loss) income, end of period $ (206,679 ) $ (42,365 ) $ (164,314 ) $ 59,900 $ 20,370 $ 39,530 Nine months ended Nine months ended September 30, 2018 September 30, 2017 Before Tax Income Tax Net Before Tax Income Tax Net Accumulated unrealized gains (loss), net, on investments available for sale, beginning of period $ 972 $ 335 $ 637 $ (13,376 ) $ (4,544 ) $ (8,832 ) Other comprehensive (loss) income before reclassification (253,656 ) (53,272 ) (200,384 ) 126,520 43,017 83,503 Reclassification adjustment for realized investment gains (loss), net, included in realized gains on investments, net 10,834 2,275 8,559 (49,234 ) (16,740 ) (32,494 ) Effect on other comprehensive (loss) income (242,822 ) (50,997 ) (191,825 ) 77,286 26,277 51,009 Accumulated unrealized (loss) gains net, on investments available for sale, end of period $ (241,850 ) $ (50,662 ) $ (191,188 ) $ 63,910 $ 21,733 $ 42,177 Accumulated unrealized gains (loss), net, on interest rate swap, beginning of period $ 7,005 $ 2,381 $ 4,624 $ (6,697 ) $ (2,277 ) $ (4,420 ) Other comprehensive income before reclassification 28,166 5,916 22,250 2,687 914 1,773 Effect on other comprehensive income 28,166 5,916 22,250 2,687 914 1,773 Accumulated unrealized income (loss), net, on interest rate swap, end of period $ 35,171 $ 8,297 $ 26,874 $ (4,010 ) $ (1,363 ) $ (2,647 ) Accumulated other comprehensive gain (loss), beginning of period $ 7,977 $ 2,716 $ 5,261 $ (20,073 ) $ (6,821 ) $ (13,252 ) Change in unrealized (loss) gains, net, on investments available for sale (242,822 ) (50,997 ) (191,825 ) 77,286 26,277 51,009 Change in unrealized gains, net, on interest rate swap 28,166 5,916 22,250 2,687 914 1,773 Effect on other comprehensive (loss) income (214,656 ) (45,081 ) (169,575 ) 79,973 27,191 52,782 Accumulated other comprehensive (loss) income, end of period $ (206,679 ) $ (42,365 ) $ (164,314 ) $ 59,900 $ 20,370 $ 39,530 |