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Investments (Fair Value and Gross Pre-Tax Net Unrealized Unrecognized Loss of Securities By Length of Time) (Details) - USD ($) $ in Thousands | Sep. 30, 2016 | Dec. 31, 2015
--- | --- | ---
AFS Fair Value, Less than 12 months |  | $ 303,470 | $ 1,449,183
AFS Unrealized Losses, Less than 12 months | [1] | (2,726) | (19,953)
AFS Fair Value, 12 months or longer |  | 79,305 | 141,580
AFS Unrealized Losses, 12 months or longer | [1] | (601) | (4,900)
AFS Fixed Income Securities [Member] |  |  |
AFS Fair Value, Less than 12 months |  | 290,942 | 1,416,504
AFS Unrealized Losses, Less than 12 months | [1] | (1,637) | (17,915)
AFS Fair Value, 12 months or longer |  | 79,305 | 141,580
AFS Unrealized Losses, 12 months or longer | [1] | (601) | (4,900)
AFS Fixed Income Securities [Member] | U.S. Government and Government Agencies [Member] |  |  |
AFS Fair Value, Less than 12 months |  |  | 16,006
AFS Unrealized Losses, Less than 12 months | [1] |  | (87)
AFS Fair Value, 12 months or longer |  |  | 396
AFS Unrealized Losses, 12 months or longer | [1] |  | (4)
AFS Fixed Income Securities [Member] | Foreign Government [Member] |  |  |
AFS Fair Value, Less than 12 months |  |  | 1,067
AFS Unrealized Losses, Less than 12 months | [1] |  | (2)
AFS Fair Value, 12 months or longer |  |  | 0
AFS Unrealized Losses, 12 months or longer | [1] |  | 0
AFS Fixed Income Securities [Member] | Obligations of States and Political Subdivisions [Member] |  |  |
AFS Fair Value, Less than 12 months |  | 74,989 | 28,617
AFS Unrealized Losses, Less than 12 months | [1] | (333) | (160)
AFS Fair Value, 12 months or longer |  | 0 | 0
AFS Unrealized Losses, 12 months or longer | [1] | 0 | 0
AFS Fixed Income Securities [Member] | Corporate Securities [Member] |  |  |
AFS Fair Value, Less than 12 months |  | 155,880 | 761,479
AFS Unrealized Losses, Less than 12 months | [1] | (1,139) | (12,671)
AFS Fair Value, 12 months or longer |  | 30,469 | 50,382
AFS Unrealized Losses, 12 months or longer | [1] | (288) | (2,850)
AFS Fixed Income Securities [Member] | Asset-Backed Securities [Member] |  |  |
AFS Fair Value, Less than 12 months |  | 21,766 | 197,477
AFS Unrealized Losses, Less than 12 months | [1] | (66) | (807)
AFS Fair Value, 12 months or longer |  | 2,450 | 12,022
AFS Unrealized Losses, 12 months or longer | [1] | (3) | (111)
AFS Fixed Income Securities [Member] | Commercial Mortgage Backed Securities [Member] |  |  |
AFS Fair Value, Less than 12 months |  | 24,633 | 146,944
AFS Unrealized Losses, Less than 12 months | [1] | (59) | (2,196)
AFS Fair Value, 12 months or longer |  | 8,709 | 15,385
AFS Unrealized Losses, 12 months or longer | [1] | (34) | (214)
AFS Fixed Income Securities [Member] | Residential Mortgage Backed Securities [Member] |  |  |
AFS Fair Value, Less than 12 months |  | 13,674 | 264,914
AFS Unrealized Losses, Less than 12 months | [1] | (40) | (1,992)
AFS Fair Value, 12 months or longer |  | 37,677 | 63,395
AFS Unrealized Losses, 12 months or longer | [1] | (276) | (1,721)
Equity Securities [Member] |  |  |
AFS Fair Value, Less than 12 months |  | 12,528 | 32,679
AFS Unrealized Losses, Less than 12 months | [1] | (1,089) | (2,038)
AFS Fair Value, 12 months or longer |  | 0 | 0
AFS Unrealized Losses, 12 months or longer | [1] | 0 | 0
Equity Securities [Member] | Common Stock [Member] |  |  |
AFS Fair Value, Less than 12 months |  | 12,528 | 31,148
AFS Unrealized Losses, Less than 12 months | [1] | (1,089) | (1,998)
AFS Fair Value, 12 months or longer |  | 0 | 0
AFS Unrealized Losses, 12 months or longer | [1] | $ 0 | 0
Equity Securities [Member] | Preferred Stock [Member] |  |  |
AFS Fair Value, Less than 12 months |  |  | 1,531
AFS Unrealized Losses, Less than 12 months | [1] |  | (40)
AFS Fair Value, 12 months or longer |  |  | 0
AFS Unrealized Losses, 12 months or longer | [1] |  | $ 0
[1] | Gross unrealized losses include non-OTTI unrealized amounts and OTTI losses recognized in AOCI.

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