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Investments (Number of Securities in an Unrealized Unrecognized Loss Position) (Details) $ in Thousands		Dec. 31, 2015 USD ($) Securities	Dec. 31, 2014 USD ($) Securities
Held To Maturity Securities Unrecognized Gains Losses Aggregate Continuous Unrealized Loss Position Twelve Months or Longer		$ 116	$ 439
Held-to-maturity Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value		0	196
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value		141,580	442,058
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss		(4,900)	(8,170)	[1]
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value		1,449,183	466,387
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss		$ (19,953)	$ (2,408)	[1]
Number of securities in an unrealized/unrecognized loss position | Securities		609	350
Unrealized Unrecognized Loss		$ 24,859	$ 10,596
Percentage Decline in Fair Value Percentage		2.00%
Held-to-maturity Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	[1]	$ 0	(3)
Held To Maturity Securities Unrecognized Gains Losses Aggregate Continuous Unrealized Loss Position Less Than Twelve Months		0	1
Held-to-maturity Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value		805	2,235
Held-to-maturity Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	[1]	(122)	(455)
Available For Sale and Held To Maturity Securities Continuous Unrealized Loss Position Less Than Twelve Months Fair Value		1,449,183	466,583
Available For Sale And Held To Maturity Securities Continuous Unrealized Loss Position Less Than Twelve Months Aggregate Losses	[1]	(19,953)	(2,411)
Held To Maturity And Available For Sale Securities Unrecognized Gains Losses Aggregate Continuous Unrealized Loss Position Less Than Twelve Months		0	1
Available For Sale and Held To Maturity Securities Continuous Unrealized Loss Position Twelve Months Or Longer Fair Value		142,385	444,293
Available For Sale And Held To Maturity Securities Continuous Unrealized Loss Position Twelve Months Or Longer Aggregate Losses	[1]	(5,022)	(8,625)
Held To Maturity And Available For Sale Securities Unrecognized Gains Losses Aggregate Continuous Unrealized Loss Position For Twelve Months Or Longer		$ 116	$ 439
Eighty Percent to Ninety-Nine Percent [Member]
Number of securities in an unrealized/unrecognized loss position | Securities		606	350
Unrealized Unrecognized Loss		$ 22,971	$ 10,596
Sixty Percent to Seventy-Nine Percent [Member]
Number of securities in an unrealized/unrecognized loss position | Securities		3	0
Unrealized Unrecognized Loss		$ 1,888	$ 0
Forty Percent to Fifty-Nine Percent [Member]
Number of securities in an unrealized/unrecognized loss position | Securities		0	0
Unrealized Unrecognized Loss		$ 0	$ 0
Twenty Percent to Thirty-Nine Percent [Member]
Number of securities in an unrealized/unrecognized loss position | Securities		0	0
Unrealized Unrecognized Loss		$ 0	$ 0
Zero Percent to Nineteen Percent [Member]
Number of securities in an unrealized/unrecognized loss position | Securities		0	0
Unrealized Unrecognized Loss		$ 0	$ 0
Afs Fixed Maturity Securities [Member]
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value		141,580	442,058
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	[1]	(4,900)	(8,170)
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value		1,416,504	461,125
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	[1]	(17,915)	(2,072)
Equity Securities [Member]
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value		0	0
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss		0	0
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value		32,679	5,262
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss		(2,038)	(336)
U.S. Government and Government Agencies [Member] | Afs Fixed Maturity Securities [Member]
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value		396	10,866
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	[1]	(4)	(115)
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value		16,006	7,567
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	[1]	(87)	(13)
Foreign Government [Member] | Afs Fixed Maturity Securities [Member]
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value		0
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	[1]	0
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value		1,067
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	[1]	(2)
Obligations of States and Political Subdivisions [Member]
Held To Maturity Securities Unrecognized Gains Losses Aggregate Continuous Unrealized Loss Position Twelve Months or Longer			0
Held-to-maturity Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value			196
Held-to-maturity Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	[1]		(3)
Held To Maturity Securities Unrecognized Gains Losses Aggregate Continuous Unrealized Loss Position Less Than Twelve Months			1
Held-to-maturity Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value			0
Held-to-maturity Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	[1]		0
Obligations of States and Political Subdivisions [Member] | Afs Fixed Maturity Securities [Member]
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value		0	64,018
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	[1]	0	(624)
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value		28,617	47,510
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	[1]	(160)	(105)
Corporate Securities [Member] | Afs Fixed Maturity Securities [Member]
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value		50,382	153,613
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	[1]	(2,850)	(4,075)
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value		761,479	276,648
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	[1]	(12,671)	(1,734)
Asset-backed Securities [Member]
Held To Maturity Securities Unrecognized Gains Losses Aggregate Continuous Unrealized Loss Position Twelve Months or Longer		116	439
Held-to-maturity Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value		0	0
Held-to-maturity Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	[1]	0	0
Held To Maturity Securities Unrecognized Gains Losses Aggregate Continuous Unrealized Loss Position Less Than Twelve Months		0	0
Held-to-maturity Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value		805	2,235
Held-to-maturity Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	[1]	(122)	(455)
Asset-backed Securities [Member] | Afs Fixed Maturity Securities [Member]
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value		12,022	15,618
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	[1]	(111)	(195)
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value		197,477	113,202
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	[1]	(807)	(178)
Commercial Mortgage Backed Securities [Member] | Afs Fixed Maturity Securities [Member]
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value		15,385	59,219
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	[1]	(214)	(743)
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value		146,944	12,799
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	[1]	(2,196)	(34)
Residential Mortgage Backed Securities [Member] | Afs Fixed Maturity Securities [Member]
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value		63,395	138,724
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	[1]	(1,721)	(2,418)
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value		264,914	3,399
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	[1]	(1,992)	(8)
Common Stock [Member] | Equity Securities [Member]
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value		0	0
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss		0	0
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value		31,148	5,262
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss		(1,998)	$ (336)
Nonredeemable Preferred Stock [Member] | Equity Securities [Member]
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value		0
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss		0
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value		1,531
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss		$ (40)
[1] Gross unrealized losses include non-OTTI unrealized amounts and OTTI losses recognized in AOCI. In addition, this column includes remaining unrealized gain or loss amounts on securities that were transferred to an HTM designation in the first quarter of 2009 for those securities that are in a net unrealized/unrecognized loss position.

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- Definition

This item represents the unrealized holding gains/losses of an available-for sale ("AFS") and held-to-maturity("HTM") security that has been in a continuous unrealized/unrecognized loss position for less than twelve months. The AFS unrealized holding losses represent the excess of amortized cost over fair value of securities. The HTM unrealized holding gains/losses represent the remaining unrealized gain/loss amounts on securities that were transferred to a HTM designation from an AFS designation as well as other-than-temporary impairment losses that are recognized in accumulated other comprehensive income.

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This item represents the unrecognized holding gains/losses of a held-to-maturity security that has been in a continuous unrealized/unrecognized loss position for less than twelve months. The unrecognized holding gains/losses represent the market value fluctuations from the later of: (i) the date a security is designated as held-to-maturity; or (ii) the date that an other-than-temporary- impairment charge is recognized on a held-to-maturity security.

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Amount of accumulated unrealized loss on investments in debt and equity securities classified as available-for-sale that have been in a continuous loss position for twelve months or longer.

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