Investments Available for Sale Securities in Unrealized Loss Position (Details) $ in Thousands		12 Months Ended
		Dec. 31, 2015 USD ($) securities	Dec. 31, 2014 USD ($) securities
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value		$ 505,312	$ 182,000
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss		(4,896)	(561)
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value		66,938	136,195
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss		(2,333)	(3,087)
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value		572,250	318,195
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Losses		$ (7,229)	$ (3,648)
Available-for-sale, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Positions | securities		113	92
Held-to-maturity Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value		$ 40,606	$ 13,871
Held-to-maturity Securities, Continuous Unrealized Loss Position, Less than 12 Months, Aggregate Loss		(262)	(26)
Held-to-maturity Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value		0	0
Held-to-maturity Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Aggregate Loss		0	0
Held-to-maturity Securities, Continuous Unrealized Loss Position, Fair Value		40,606	13,871
Held-to-maturity Securities, Continuous Unrealized Loss Position, Aggregate Loss		$ (262)	$ (26)
Held-to-maturity, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Positions | securities		5	1
US Government and Government Agencies and Authorities [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value		$ 4,935	$ 10,364
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss		(18)	(4)
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value		1,001	632
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss		(9)	(40)
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value		5,936	10,996
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Losses		$ (27)	$ (44)
Available-for-sale, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Positions | securities		3	2
US Government-sponsored Enterprises Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value		$ 167,691	$ 51,980
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss		(1,345)	(99)
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value		0	28,957
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss		0	(169)
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value		167,691	80,937
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Losses		$ (1,345)	$ (268)
Available-for-sale, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Positions | securities		24	8
Municipal Bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value		$ 14,483	$ 62,871
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss		(43)	(255)
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value		3,173	15,473
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss		(73)	(180)
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value		17,656	78,344
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Losses		$ (116)	$ (435)
Available-for-sale, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Positions | securities		12	41
Mortgage Backed Securities, Other [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value	[1]	$ 318,156	$ 56,711
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	[1]	(3,486)	(192)
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value	[1]	62,753	91,133
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	[1]	(2,248)	(2,698)
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value		380,909	147,844
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Losses		$ (5,734)	$ (2,890)
Available-for-sale, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Positions | securities	[1]	68	34
Held-to-maturity Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value	[1]	$ 40,606	$ 13,871
Held-to-maturity Securities, Continuous Unrealized Loss Position, Less than 12 Months, Aggregate Loss	[1]	(262)	(26)
Held-to-maturity Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value	[1]	0	0
Held-to-maturity Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Aggregate Loss	[1]	0	0
Held-to-maturity Securities, Continuous Unrealized Loss Position, Fair Value	[1]	40,606	13,871
Held-to-maturity Securities, Continuous Unrealized Loss Position, Aggregate Loss	[1]	$ (262)	$ (26)
Held-to-maturity, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Positions | securities	[1]	5	1
Other Aggregated Investments [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value		$ 47	$ 74
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss		(4)	(11)
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value		11	0
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss		(3)	0
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value		58	74
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Losses		$ (7)	$ (11)
Available-for-sale, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Positions | securities		6	7

[1] All mortgage-backed securities are guaranteed by U.S. government agencies or Government-sponsored entities.