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Investments (Fair Value and Gross Pre-Tax Net Unrealized Loss of Securities By Length of Time) (Details) - USD ($) $ in Thousands | Mar. 31, 2019 | Dec. 31, 2018
--- | --- | ---
Percent Of Securities of Amortized Cost In An Unrealized Unrecognized Loss Position |  | 1.00% | 2.00%
AFS Fixed Income Securities [Member] |  |  |
AFS Fair Value, Less than 12 months |  | $ 688,988 | $ 2,142,433
AFS Unrealized Losses, Less than 12 months | [1] | (7,889) | (36,948)
AFS Fair Value, 12 months or longer |  | 438,135 | 275,174
AFS Unrealized Losses, 12 months or longer | [1] | (6,399) | (8,119)
AFS Fair Value |  | 1,127,123 | 2,417,607
AFS Unrealized Losses | [1] | (14,288) | (45,067)
AFS Fixed Income Securities [Member] | U.S. Government and Government Agencies [Member] |  |  |
AFS Fair Value, Less than 12 months |  | 13,443 | 6,693
AFS Unrealized Losses, Less than 12 months | [1] | (41) | (174)
AFS Fair Value, 12 months or longer |  | 25,774 | 23,163
AFS Unrealized Losses, 12 months or longer | [1] | (300) | (418)
AFS Fair Value |  | 39,217 | 29,856
AFS Unrealized Losses | [1] | (341) | (592)
AFS Fixed Income Securities [Member] | Foreign Government [Member] |  |  |
AFS Fair Value, Less than 12 months |  | 0 | 12,208
AFS Unrealized Losses, Less than 12 months | [1] | 0 | (93)
AFS Fair Value, 12 months or longer |  | 3,509 | 1,482
AFS Unrealized Losses, 12 months or longer | [1] | (11) | (14)
AFS Fair Value |  | 3,509 | 13,690
AFS Unrealized Losses | [1] | (11) | (107)
AFS Fixed Income Securities [Member] | Obligations of States and Political Subdivisions [Member] |  |  |
AFS Fair Value, Less than 12 months |  | 15,257 | 196,798
AFS Unrealized Losses, Less than 12 months | [1] | (71) | (2,074)
AFS Fair Value, 12 months or longer |  | 21,676 | 42,821
AFS Unrealized Losses, 12 months or longer | [1] | (126) | (557)
AFS Fair Value |  | 36,933 | 239,619
AFS Unrealized Losses | [1] | (197) | (2,631)
AFS Fixed Income Securities [Member] | Corporate Securities [Member] |  |  |
AFS Fair Value, Less than 12 months |  | 158,607 | 1,041,952
AFS Unrealized Losses, Less than 12 months | [1] | (2,783) | (23,649)
AFS Fair Value, 12 months or longer |  | 160,121 | 78,953
AFS Unrealized Losses, 12 months or longer | [1] | (3,330) | (4,316)
AFS Fair Value |  | 318,728 | 1,120,905
AFS Unrealized Losses | [1] | (6,113) | (27,965)
AFS Fixed Income Securities [Member] | Collateralized Loan Obligations and Other Asset Backed Securities [Member] |  |  |
AFS Fair Value, Less than 12 months |  | 366,775 | 516,106
AFS Unrealized Losses, Less than 12 months | [1] | (4,231) | (6,750)
AFS Fair Value, 12 months or longer |  | 79,489 | 16,800
AFS Unrealized Losses, 12 months or longer | [1] | (1,152) | (193)
AFS Fair Value |  | 446,264 | 532,906
AFS Unrealized Losses | [1] | (5,383) | (6,943)
AFS Fixed Income Securities [Member] | Commercial Mortgage Backed Securities [Member] |  |  |
AFS Fair Value, Less than 12 months |  | 112,025 | 229,338
AFS Unrealized Losses, Less than 12 months | [1] | (505) | (2,548)
AFS Fair Value, 12 months or longer |  | 63,774 | 66,294
AFS Unrealized Losses, 12 months or longer | [1] | (310) | (1,200)
AFS Fair Value |  | 175,799 | 295,632
AFS Unrealized Losses | [1] | (815) | (3,748)
AFS Fixed Income Securities [Member] | Residential Mortgage Backed Securities [Member] |  |  |
AFS Fair Value, Less than 12 months |  | 22,881 | 139,338
AFS Unrealized Losses, Less than 12 months | [1] | (258) | (1,660)
AFS Fair Value, 12 months or longer |  | 83,792 | 45,661
AFS Unrealized Losses, 12 months or longer | [1] | (1,170) | (1,421)
AFS Fair Value |  | 106,673 | 184,999
AFS Unrealized Losses | [1] | $ (1,428) | $ (3,081)
[1] | Gross unrealized losses include non-OTTI unrealized amounts and OTTI losses recognized in AOCI.

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