Available for Sale Securities (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended					72 Months Ended
	Dec. 31, 2014		Dec. 31, 2013		Dec. 31, 2012	Dec. 31, 2014
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Amortized Cost	$ 8,881,990		$ 10,185,091			$ 8,881,990
Available-for-sale Securities, Fair Value	8,978,945		10,147,162			8,978,945
Available-for-sale Securities, Gross Unrealized Gain	129,876	[1]	120,120	[1]		129,876	[1]
Available-for-sale Securities, Gross Unrealized Loss	(32,257)	[1]	(155,607)	[1]		(32,257)	[1]
Available-for-sale Securities, Other Than Temporary Impairments	(664)	[2]	(2,442)	[2]		(664)	[2]
Available-for-sale Securities, Debt Maturities, Nominal Yield [Abstract]
Available-for-sale Securities, Debt Maturities, Nominal Yield	1.85%					1.85%
Available-for-sale Securities, Gross Realized Gain (Loss), Disclosures [Abstract]
Available-for-sale Securities, Proceeds	2,664,740		2,436,093		1,744,662
Available-for-sale Securities, Gross realized gains	24,923		25,711		41,191
Available-for-sale Securities, Gross realized losses	(23,384)		(14,991)		(7,346)
Available-for-sale Securites, Related federal and state income tax expense	599		4,170		13,166
Available-for-sale Securities, Pledged as Collateral [Abstract]
Available-for-sale Securities, Pledged As Collateral, Amortized cost	5,855,220		5,171,782			5,855,220
Available-for-sale Securities, Pledged As Collateral, Fair value	5,893,972		5,133,530			5,893,972
Available-for-sale Securities, Continuous Unrealized Loss Position, Qualitative Disclosure [Abstract]
Available-for-sale, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Securities	255		446			255
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value [Abstract]
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value	577,473		6,230,595			577,473
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value	2,160,051		50,865			2,160,051
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	2,737,524		6,281,460			2,737,524
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Losses [Abstract]
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	1,446		156,172			1,446
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	31,475		1,877			31,475
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss	32,921		158,049			32,921
Other than Temporary Impairment Losses, Investments, Available-for-sale Securities, Portion Recognized In Earnings, Net Qualitative Disclosures, Lowest Current Credit Rating [Abstract]
Available-for-sale Securities, Portfolio Concentration US Govt or GSE Securities Not Rated, Amortized Cost	8,614,400	[3]				8,614,400	[3]
Available-for-sale Securities, Portfolio Concentration US Govt or GSE Securities Not Rated, Fair Value	8,696,498	[3]				8,696,498	[3]
Available-for-sale securities, Portfolio Concentration Rated AAA To AA, Amortized Cost	44,915					44,915
Available-for-sale Securities, Portfolio Concentration Rated AAA To AA, Fair Value	46,245					46,245
Available-for-sale Securities, Portfolio Concentration Rated A To BBB, Amortized Cost	27,497					27,497
Available-for-sale Securities, Portfolio Concentration Rated A To BBB, Fair Value	28,087					28,087
Available-for-sale Securities, Portfolio Concentration Rated Below Investment Grade, Amortized Cost	165,125					165,125
Available-for-sale Securities, Portfolio Concentration Rated Below Investment Grade, Fair Value	177,726					177,726
Available-for-sale Securities, Portfolio Concentration Not Rated, Amortized Cost	30,053					30,053
Available-for-sale Securities, Portfolio Concentration Not Rated, Fair Value	30,389					30,389
Fixed maturity securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Amortized Cost	2,137,552					2,137,552
Available-for-sale Securities, Fair Value	2,122,383					2,122,383
Available-for-sale Securities, Debt Maturities, Amortized Cost, Rolling Maturity [Abstract]
Available-for-sale Securities, Debt Maturities, Less than One Year, Amortized Cost	13,177					13,177
Available-for-sale Securities, Debt Maturities, One to Five Years, Amortized Cost	941,928					941,928
Available-for-sale Securities, Debt Maturities, Six to Ten Years, Amortized Cost	811,080					811,080
Available-for-sale Securities, Debt Maturities, Over Ten Years, Amortized Cost	371,367					371,367
Available-for-sale Securities, Debt Maturities, Fair Value, Rolling Maturity [Abstract]
Available-for-sale Securities, Debt Maturities, Less Than One Year, Fair Value	13,267					13,267
Available-for-sale Securities, Debt Maturities, One to Five Years, Fair Value	936,684					936,684
Available-for-sale Securities, Debt Maturities, Six to Ten Years, Fair Value	805,820					805,820
Available-for-sale Securities, Debt Maturities, Over Ten Years, Fair Value	366,612					366,612
Available-for-sale Securities, Debt Maturities, Nominal Yield [Abstract]
Available-for-sale Securities, Debt Maturities, Less than One Year, Nominal Yield	2.82%					2.82%
Available-for-sale Securities, Debt Maturities, One to Five Years, Nominal Yield	1.52%					1.52%
Available-for-sale Securities, Debt Maturities, Six to Ten Years, Nominal Yield	1.69%					1.69%
Available-for-sale Securities, Debt Maturities, Greater Than Ten Years, Nominal Yield	1.38%					1.38%
Available-for-sale Securities, Debt Maturities, Nominal Yield	1.57%					1.57%
Available-for-sale Securities, Debt Maturities, Weighted Average Maturity	8.58	[4]				8.58	[4]
U.S. Treasury securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Amortized Cost	1,005		1,042			1,005
Available-for-sale Securities, Fair Value	1,005		1,042			1,005
Available-for-sale Securities, Gross Unrealized Gain	0	[1]	0	[1]		0	[1]
Available-for-sale Securities, Gross Unrealized Loss	0	[1]	0	[1]		0	[1]
Available-for-sale Securities, Other Than Temporary Impairments	0	[2]	0	[2]		0	[2]
Available-for-sale Securities, Debt Maturities, Amortized Cost, Rolling Maturity [Abstract]
Available-for-sale Securities, Debt Maturities, Less than One Year, Amortized Cost	1,005					1,005
Available-for-sale Securities, Debt Maturities, One to Five Years, Amortized Cost	0					0
Available-for-sale Securities, Debt Maturities, Six to Ten Years, Amortized Cost	0					0
Available-for-sale Securities, Debt Maturities, Over Ten Years, Amortized Cost	0					0
Available-for-sale Securities, Debt Maturities, Fair Value, Rolling Maturity [Abstract]
Available-for-sale Securities, Debt Maturities, Less Than One Year, Fair Value	1,005					1,005
Available-for-sale Securities, Debt Maturities, One to Five Years, Fair Value	0					0
Available-for-sale Securities, Debt Maturities, Six to Ten Years, Fair Value	0					0
Available-for-sale Securities, Debt Maturities, Over Ten Years, Fair Value	0					0
Available-for-sale Securities, Debt Maturities, Nominal Yield [Abstract]
Available-for-sale Securities, Debt Maturities, Less than One Year, Nominal Yield	0.24%					0.24%
Available-for-sale Securities, Debt Maturities, One to Five Years, Nominal Yield	0.00%					0.00%
Available-for-sale Securities, Debt Maturities, Six to Ten Years, Nominal Yield	0.00%					0.00%
Available-for-sale Securities, Debt Maturities, Greater Than Ten Years, Nominal Yield	0.00%					0.00%
Available-for-sale Securities, Debt Maturities, Nominal Yield	0.24%					0.24%
Available-for-sale Securities, Debt Maturities, Weighted Average Maturity	0.13	[4]				0.13	[4]
Other than Temporary Impairment Losses, Investments, Available-for-sale Securities, Portion Recognized In Earnings, Net Qualitative Disclosures, Lowest Current Credit Rating [Abstract]
Available-for-sale Securities, Portfolio Concentration US Govt or GSE Securities Not Rated, Amortized Cost	1,005	[3]				1,005	[3]
Available-for-sale Securities, Portfolio Concentration US Govt or GSE Securities Not Rated, Fair Value	1,005	[3]				1,005	[3]
Available-for-sale securities, Portfolio Concentration Rated AAA To AA, Amortized Cost	0					0
Available-for-sale Securities, Portfolio Concentration Rated AAA To AA, Fair Value	0					0
Available-for-sale Securities, Portfolio Concentration Rated A To BBB, Amortized Cost	0					0
Available-for-sale Securities, Portfolio Concentration Rated A To BBB, Fair Value	0					0
Available-for-sale Securities, Portfolio Concentration Rated Below Investment Grade, Amortized Cost	0					0
Available-for-sale Securities, Portfolio Concentration Rated Below Investment Grade, Fair Value	0					0
Available-for-sale Securities, Portfolio Concentration Not Rated, Amortized Cost	0					0
Available-for-sale Securities, Portfolio Concentration Not Rated, Fair Value	0					0
Municipal and other tax-exempt securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Amortized Cost	63,018		73,232			63,018
Available-for-sale Securities, Fair Value	63,557		73,775			63,557
Available-for-sale Securities, Gross Unrealized Gain	1,280	[1]	1,606	[1]		1,280	[1]
Available-for-sale Securities, Gross Unrealized Loss	(741)	[1]	(1,063)	[1]		(741)	[1]
Available-for-sale Securities, Other Than Temporary Impairments	0	[2]	0	[2]		0	[2]
Available-for-sale Securities, Debt Maturities, Amortized Cost, Rolling Maturity [Abstract]
Available-for-sale Securities, Debt Maturities, Less than One Year, Amortized Cost	7,134					7,134
Available-for-sale Securities, Debt Maturities, One to Five Years, Amortized Cost	29,750					29,750
Available-for-sale Securities, Debt Maturities, Six to Ten Years, Amortized Cost	2,288					2,288
Available-for-sale Securities, Debt Maturities, Over Ten Years, Amortized Cost	23,846					23,846
Available-for-sale Securities, Debt Maturities, Fair Value, Rolling Maturity [Abstract]
Available-for-sale Securities, Debt Maturities, Less Than One Year, Fair Value	7,197					7,197
Available-for-sale Securities, Debt Maturities, One to Five Years, Fair Value	30,603					30,603
Available-for-sale Securities, Debt Maturities, Six to Ten Years, Fair Value	2,496					2,496
Available-for-sale Securities, Debt Maturities, Over Ten Years, Fair Value	23,261					23,261
Available-for-sale Securities, Debt Maturities, Nominal Yield [Abstract]
Available-for-sale Securities, Debt Maturities, Less than One Year, Nominal Yield	3.68%	[5]				3.68%	[5]
Available-for-sale Securities, Debt Maturities, One to Five Years, Nominal Yield	4.05%	[5]				4.05%	[5]
Available-for-sale Securities, Debt Maturities, Six to Ten Years, Nominal Yield	6.48%	[5]				6.48%	[5]
Available-for-sale Securities, Debt Maturities, Greater Than Ten Years, Nominal Yield	1.92%	[5],[6]				1.92%	[5],[6]
Available-for-sale Securities, Debt Maturities, Nominal Yield	3.29%	[5]				3.29%	[5]
Available-for-sale Securities, Debt Maturities, Weighted Average Maturity	8.27	[4]				8.27	[4]
Available-for-sale Securities, Debt Maturities, Effective tax rate for nominal yield calculation	39.00%					39.00%
Available-for-sale Securities, Debt Maturities, Number of days for interest rates to reset	35 days
Available-for-sale Securities, Continuous Unrealized Loss Position, Qualitative Disclosure [Abstract]
Available-for-sale, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Securities	22		27			22
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value [Abstract]
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value	10,838		13,286			10,838
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value	12,176		17,805			12,176
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	23,014		31,091			23,014
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Losses [Abstract]
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	12		245			12
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	729		818			729
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss	741		1,063			741
Other than Temporary Impairment Losses, Investments, Available-for-sale Securities, Portion Recognized In Earnings, Net Qualitative Disclosures, Lowest Current Credit Rating [Abstract]
Available-for-sale Securities, Portfolio Concentration US Govt or GSE Securities Not Rated, Amortized Cost	0	[3]				0	[3]
Available-for-sale Securities, Portfolio Concentration US Govt or GSE Securities Not Rated, Fair Value	0	[3]				0	[3]
Available-for-sale securities, Portfolio Concentration Rated AAA To AA, Amortized Cost	40,511					40,511
Available-for-sale Securities, Portfolio Concentration Rated AAA To AA, Fair Value	41,579					41,579
Available-for-sale Securities, Portfolio Concentration Rated A To BBB, Amortized Cost	11,053					11,053
Available-for-sale Securities, Portfolio Concentration Rated A To BBB, Fair Value	10,516					10,516
Available-for-sale Securities, Portfolio Concentration Rated Below Investment Grade, Amortized Cost	0					0
Available-for-sale Securities, Portfolio Concentration Rated Below Investment Grade, Fair Value	0					0
Available-for-sale Securities, Portfolio Concentration Not Rated, Amortized Cost	11,454					11,454
Available-for-sale Securities, Portfolio Concentration Not Rated, Fair Value	11,462					11,462
Other Than Temporary Impairment Losses, Investments, Available-for-sale Securities, Portion Recognized in Earnings, Net, Qualitative Disclosures, Assumptions Used to Develop Projected Cash Flows [Abstract]
Available-for-sale Securities, Other than Temporary Impairment Losses, Credit Losses Recognized	0		1,400		1,000
Commercial mortgage-backed securities guaranteed by U.S. government agencies [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Amortized Cost	2,064,091		2,100,146			2,064,091
Available-for-sale Securities, Fair Value	2,048,609		2,055,804			2,048,609
Available-for-sale Securities, Gross Unrealized Gain	4,437	[1]	1,042	[1]		4,437	[1]
Available-for-sale Securities, Gross Unrealized Loss	(19,919)	[1]	(45,384)	[1]		(19,919)	[1]
Available-for-sale Securities, Other Than Temporary Impairments	0	[2]	0	[2]		0	[2]
Available-for-sale Securities, Debt Maturities, Amortized Cost, Rolling Maturity [Abstract]
Available-for-sale Securities, Debt Maturities, Less than One Year, Amortized Cost	0					0
Available-for-sale Securities, Debt Maturities, One to Five Years, Amortized Cost	912,178					912,178
Available-for-sale Securities, Debt Maturities, Six to Ten Years, Amortized Cost	808,792					808,792
Available-for-sale Securities, Debt Maturities, Over Ten Years, Amortized Cost	343,121					343,121
Available-for-sale Securities, Debt Maturities, Fair Value, Rolling Maturity [Abstract]
Available-for-sale Securities, Debt Maturities, Less Than One Year, Fair Value	0					0
Available-for-sale Securities, Debt Maturities, One to Five Years, Fair Value	906,081					906,081
Available-for-sale Securities, Debt Maturities, Six to Ten Years, Fair Value	803,324					803,324
Available-for-sale Securities, Debt Maturities, Over Ten Years, Fair Value	339,204					339,204
Available-for-sale Securities, Debt Maturities, Nominal Yield [Abstract]
Available-for-sale Securities, Debt Maturities, Less than One Year, Nominal Yield	0.00%					0.00%
Available-for-sale Securities, Debt Maturities, One to Five Years, Nominal Yield	1.43%					1.43%
Available-for-sale Securities, Debt Maturities, Six to Ten Years, Nominal Yield	1.68%					1.68%
Available-for-sale Securities, Debt Maturities, Greater Than Ten Years, Nominal Yield	1.33%					1.33%
Available-for-sale Securities, Debt Maturities, Nominal Yield	1.51%					1.51%
Available-for-sale Securities, Debt Maturities, Weighted Average Maturity	8.56	[4]				8.56	[4]
Available-for-sale Securities, Continuous Unrealized Loss Position, Qualitative Disclosure [Abstract]
Available-for-sale, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Securities	104		123			104
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value [Abstract]
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value	223,106		1,800,717			223,106
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value	1,238,376		2,286			1,238,376
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	1,461,482		1,803,003			1,461,482
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Losses [Abstract]
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	454		45,302			454
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	19,465		82			19,465
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss	19,919		45,384			19,919
Other than Temporary Impairment Losses, Investments, Available-for-sale Securities, Portion Recognized In Earnings, Net Qualitative Disclosures, Lowest Current Credit Rating [Abstract]
Available-for-sale Securities, Portfolio Concentration US Govt or GSE Securities Not Rated, Amortized Cost	2,064,091	[3]				2,064,091	[3]
Available-for-sale Securities, Portfolio Concentration US Govt or GSE Securities Not Rated, Fair Value	2,048,609	[3]				2,048,609	[3]
Available-for-sale securities, Portfolio Concentration Rated AAA To AA, Amortized Cost	0					0
Available-for-sale Securities, Portfolio Concentration Rated AAA To AA, Fair Value	0					0
Available-for-sale Securities, Portfolio Concentration Rated A To BBB, Amortized Cost	0					0
Available-for-sale Securities, Portfolio Concentration Rated A To BBB, Fair Value	0					0
Available-for-sale Securities, Portfolio Concentration Rated Below Investment Grade, Amortized Cost	0					0
Available-for-sale Securities, Portfolio Concentration Rated Below Investment Grade, Fair Value	0					0
Available-for-sale Securities, Portfolio Concentration Not Rated, Amortized Cost	0					0
Available-for-sale Securities, Portfolio Concentration Not Rated, Fair Value	0					0
Other debt securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Amortized Cost	9,438		35,061			9,438
Available-for-sale Securities, Fair Value	9,212		35,241			9,212
Available-for-sale Securities, Gross Unrealized Gain	26	[1]	368	[1]		26	[1]
Available-for-sale Securities, Gross Unrealized Loss	(252)	[1]	(188)	[1]		(252)	[1]
Available-for-sale Securities, Other Than Temporary Impairments	0	[2]	0	[2]		0	[2]
Available-for-sale Securities, Debt Maturities, Amortized Cost, Rolling Maturity [Abstract]
Available-for-sale Securities, Debt Maturities, Less than One Year, Amortized Cost	5,038					5,038
Available-for-sale Securities, Debt Maturities, One to Five Years, Amortized Cost	0					0
Available-for-sale Securities, Debt Maturities, Six to Ten Years, Amortized Cost	0					0
Available-for-sale Securities, Debt Maturities, Over Ten Years, Amortized Cost	4,400					4,400
Available-for-sale Securities, Debt Maturities, Fair Value, Rolling Maturity [Abstract]
Available-for-sale Securities, Debt Maturities, Less Than One Year, Fair Value	5,065					5,065
Available-for-sale Securities, Debt Maturities, One to Five Years, Fair Value	0					0
Available-for-sale Securities, Debt Maturities, Six to Ten Years, Fair Value	0					0
Available-for-sale Securities, Debt Maturities, Over Ten Years, Fair Value	4,147					4,147
Available-for-sale Securities, Debt Maturities, Nominal Yield [Abstract]
Available-for-sale Securities, Debt Maturities, Less than One Year, Nominal Yield	2.12%					2.12%
Available-for-sale Securities, Debt Maturities, One to Five Years, Nominal Yield	0.00%					0.00%
Available-for-sale Securities, Debt Maturities, Six to Ten Years, Nominal Yield	0.00%					0.00%
Available-for-sale Securities, Debt Maturities, Greater Than Ten Years, Nominal Yield	1.71%					1.71%
Available-for-sale Securities, Debt Maturities, Nominal Yield	1.93%					1.93%
Available-for-sale Securities, Debt Maturities, Weighted Average Maturity	15.38	[4]				15.38	[4]
Available-for-sale Securities, Continuous Unrealized Loss Position, Qualitative Disclosure [Abstract]
Available-for-sale, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Securities	2		3			2
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value [Abstract]
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value	0		4,712			0
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value	4,150		0			4,150
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	4,150		4,712			4,150
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Losses [Abstract]
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	0		188			0
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	252		0			252
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss	252		188			252
Other than Temporary Impairment Losses, Investments, Available-for-sale Securities, Portion Recognized In Earnings, Net Qualitative Disclosures, Lowest Current Credit Rating [Abstract]
Available-for-sale Securities, Portfolio Concentration US Govt or GSE Securities Not Rated, Amortized Cost	0	[3]				0	[3]
Available-for-sale Securities, Portfolio Concentration US Govt or GSE Securities Not Rated, Fair Value	0	[3]				0	[3]
Available-for-sale securities, Portfolio Concentration Rated AAA To AA, Amortized Cost	4,400					4,400
Available-for-sale Securities, Portfolio Concentration Rated AAA To AA, Fair Value	4,149					4,149
Available-for-sale Securities, Portfolio Concentration Rated A To BBB, Amortized Cost	5,038					5,038
Available-for-sale Securities, Portfolio Concentration Rated A To BBB, Fair Value	5,063					5,063
Available-for-sale Securities, Portfolio Concentration Rated Below Investment Grade, Amortized Cost	0					0
Available-for-sale Securities, Portfolio Concentration Rated Below Investment Grade, Fair Value	0					0
Available-for-sale Securities, Portfolio Concentration Not Rated, Amortized Cost	0					0
Available-for-sale Securities, Portfolio Concentration Not Rated, Fair Value	0					0
Residential mortgage-backed securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Amortized Cost	6,703,664		7,934,370			6,703,664
Available-for-sale Securities, Fair Value	6,812,841		7,937,109			6,812,841
Available-for-sale Securities, Gross Unrealized Gain	121,079	[1]	114,073	[1]		121,079	[1]
Available-for-sale Securities, Gross Unrealized Loss	(11,238)	[1]	(108,892)	[1]		(11,238)	[1]
Available-for-sale Securities, Other Than Temporary Impairments	(664)	[2]	(2,442)	[2]		(664)	[2]
Available-for-sale Securities, Debt Maturities, Nominal Yield [Abstract]
Available-for-sale Securities, Debt Maturities, Nominal Yield	1.95%	[7]				1.95%	[7]
Available-for-sale Securities, Debt Maturities, Average Expected Life of Mortgage-backed Securities	3 years 5 months
Available-for-sale Securities, Continuous Unrealized Loss Position, Qualitative Disclosure [Abstract]
Available-for-sale, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Securities	57		174			57
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value [Abstract]
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value	340,631		4,404,822			340,631
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value	904,144		30,774			904,144
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	1,244,775		4,435,596			1,244,775
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Losses [Abstract]
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	903		110,357			903
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	10,999		977			10,999
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss	11,902		111,334			11,902
Other than Temporary Impairment Losses, Investments, Available-for-sale Securities, Portion Recognized In Earnings, Net Qualitative Disclosures, Lowest Current Credit Rating [Abstract]
Available-for-sale Securities, Portfolio Concentration US Govt or GSE Securities Not Rated, Amortized Cost	6,549,304	[3]				6,549,304	[3]
Available-for-sale Securities, Portfolio Concentration US Govt or GSE Securities Not Rated, Fair Value	6,646,884	[3]				6,646,884	[3]
Available-for-sale securities, Portfolio Concentration Rated AAA To AA, Amortized Cost	0					0
Available-for-sale Securities, Portfolio Concentration Rated AAA To AA, Fair Value	0					0
Available-for-sale Securities, Portfolio Concentration Rated A To BBB, Amortized Cost	0					0
Available-for-sale Securities, Portfolio Concentration Rated A To BBB, Fair Value	0					0
Available-for-sale Securities, Portfolio Concentration Rated Below Investment Grade, Amortized Cost	154,360					154,360
Available-for-sale Securities, Portfolio Concentration Rated Below Investment Grade, Fair Value	165,957					165,957
Available-for-sale Securities, Portfolio Concentration Not Rated, Amortized Cost	0					0
Available-for-sale Securities, Portfolio Concentration Not Rated, Fair Value	0					0
U.S. government agency residential mortgage-backed securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Amortized Cost	6,549,304		7,720,189			6,549,304
Available-for-sale Securities, Fair Value	6,646,884		7,716,010			6,646,884
Available-for-sale Securities, Gross Unrealized Gain	108,818	[1]	104,713	[1]		108,818	[1]
Available-for-sale Securities, Gross Unrealized Loss	(11,238)	[1]	(108,892)	[1]		(11,238)	[1]
Available-for-sale Securities, Other Than Temporary Impairments	0	[2]	0	[2]		0	[2]
Available-for-sale Securities, Continuous Unrealized Loss Position, Qualitative Disclosure [Abstract]
Available-for-sale, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Securities	45		158			45
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value [Abstract]
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value	329,354		4,379,137			329,354
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value	894,124		0			894,124
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	1,223,478		4,379,137			1,223,478
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Losses [Abstract]
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	596		108,892			596
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	10,642		0			10,642
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss	11,238		108,892			11,238
Other than Temporary Impairment Losses, Investments, Available-for-sale Securities, Portion Recognized In Earnings, Net Qualitative Disclosures, Lowest Current Credit Rating [Abstract]
Available-for-sale Securities, Portfolio Concentration US Govt or GSE Securities Not Rated, Amortized Cost	6,549,304	[3]				6,549,304	[3]
Available-for-sale Securities, Portfolio Concentration US Govt or GSE Securities Not Rated, Fair Value	6,646,884	[3]				6,646,884	[3]
Available-for-sale securities, Portfolio Concentration Rated AAA To AA, Amortized Cost	0					0
Available-for-sale Securities, Portfolio Concentration Rated AAA To AA, Fair Value	0					0
Available-for-sale Securities, Portfolio Concentration Rated A To BBB, Amortized Cost	0					0
Available-for-sale Securities, Portfolio Concentration Rated A To BBB, Fair Value	0					0
Available-for-sale Securities, Portfolio Concentration Rated Below Investment Grade, Amortized Cost	0					0
Available-for-sale Securities, Portfolio Concentration Rated Below Investment Grade, Fair Value	0					0
Available-for-sale Securities, Portfolio Concentration Not Rated, Amortized Cost	0					0
Available-for-sale Securities, Portfolio Concentration Not Rated, Fair Value	0					0
U.S. government agency residential mortgage-backed securities [Member] | Federal National Mortgage Association Certificates and Obligations (FNMA) [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Amortized Cost	3,932,200		4,224,327			3,932,200
Available-for-sale Securities, Fair Value	3,997,428		4,232,332			3,997,428
Available-for-sale Securities, Gross Unrealized Gain	71,200	[1]	68,154	[1]		71,200	[1]
Available-for-sale Securities, Gross Unrealized Loss	(5,972)	[1]	(60,149)	[1]		(5,972)	[1]
Available-for-sale Securities, Other Than Temporary Impairments	0	[2]	0	[2]		0	[2]
Available-for-sale Securities, Continuous Unrealized Loss Position, Qualitative Disclosure [Abstract]
Available-for-sale, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Securities	24		81			24
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value [Abstract]
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value	257,854		2,281,491			257,854
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value	454,394		0			454,394
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	712,248		2,281,491			712,248
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Losses [Abstract]
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	547		60,149			547
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	5,425		0			5,425
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss	5,972		60,149			5,972
Other than Temporary Impairment Losses, Investments, Available-for-sale Securities, Portion Recognized In Earnings, Net Qualitative Disclosures, Lowest Current Credit Rating [Abstract]
Available-for-sale Securities, Portfolio Concentration US Govt or GSE Securities Not Rated, Amortized Cost	3,932,200	[3]				3,932,200	[3]
Available-for-sale Securities, Portfolio Concentration US Govt or GSE Securities Not Rated, Fair Value	3,997,428	[3]				3,997,428	[3]
Available-for-sale securities, Portfolio Concentration Rated AAA To AA, Amortized Cost	0					0
Available-for-sale Securities, Portfolio Concentration Rated AAA To AA, Fair Value	0					0
Available-for-sale Securities, Portfolio Concentration Rated A To BBB, Amortized Cost	0					0
Available-for-sale Securities, Portfolio Concentration Rated A To BBB, Fair Value	0					0
Available-for-sale Securities, Portfolio Concentration Rated Below Investment Grade, Amortized Cost	0					0
Available-for-sale Securities, Portfolio Concentration Rated Below Investment Grade, Fair Value	0					0
Available-for-sale Securities, Portfolio Concentration Not Rated, Amortized Cost	0					0
Available-for-sale Securities, Portfolio Concentration Not Rated, Fair Value	0					0
U.S. government agency residential mortgage-backed securities [Member] | Federal Home Loan Mortgage Corporation Certificates and Obligations (FHLMC) [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Amortized Cost	1,810,476		2,308,341			1,810,476
Available-for-sale Securities, Fair Value	1,836,870		2,293,943			1,836,870
Available-for-sale Securities, Gross Unrealized Gain	29,043	[1]	25,813	[1]		29,043	[1]
Available-for-sale Securities, Gross Unrealized Loss	(2,649)	[1]	(40,211)	[1]		(2,649)	[1]
Available-for-sale Securities, Other Than Temporary Impairments	0	[2]	0	[2]		0	[2]
Available-for-sale Securities, Continuous Unrealized Loss Position, Qualitative Disclosure [Abstract]
Available-for-sale, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Securities	16		50			16
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value [Abstract]
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value	62,950		1,450,588			62,950
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value	310,834		0			310,834
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	373,784		1,450,588			373,784
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Losses [Abstract]
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	37		40,211			37
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	2,612		0			2,612
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss	2,649		40,211			2,649
Other than Temporary Impairment Losses, Investments, Available-for-sale Securities, Portion Recognized In Earnings, Net Qualitative Disclosures, Lowest Current Credit Rating [Abstract]
Available-for-sale Securities, Portfolio Concentration US Govt or GSE Securities Not Rated, Amortized Cost	1,810,476	[3]				1,810,476	[3]
Available-for-sale Securities, Portfolio Concentration US Govt or GSE Securities Not Rated, Fair Value	1,836,870	[3]				1,836,870	[3]
Available-for-sale securities, Portfolio Concentration Rated AAA To AA, Amortized Cost	0					0
Available-for-sale Securities, Portfolio Concentration Rated AAA To AA, Fair Value	0					0
Available-for-sale Securities, Portfolio Concentration Rated A To BBB, Amortized Cost	0					0
Available-for-sale Securities, Portfolio Concentration Rated A To BBB, Fair Value	0					0
Available-for-sale Securities, Portfolio Concentration Rated Below Investment Grade, Amortized Cost	0					0
Available-for-sale Securities, Portfolio Concentration Rated Below Investment Grade, Fair Value	0					0
Available-for-sale Securities, Portfolio Concentration Not Rated, Amortized Cost	0					0
Available-for-sale Securities, Portfolio Concentration Not Rated, Fair Value	0					0
U.S. government agency residential mortgage-backed securities [Member] | Government National Mortgage Association Certificates and Obligations (GNMA) [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Amortized Cost	801,820		1,151,225			801,820
Available-for-sale Securities, Fair Value	807,443		1,152,128			807,443
Available-for-sale Securities, Gross Unrealized Gain	8,240	[1]	9,435	[1]		8,240	[1]
Available-for-sale Securities, Gross Unrealized Loss	(2,617)	[1]	(8,532)	[1]		(2,617)	[1]
Available-for-sale Securities, Other Than Temporary Impairments	0	[2]	0	[2]		0	[2]
Available-for-sale Securities, Continuous Unrealized Loss Position, Qualitative Disclosure [Abstract]
Available-for-sale, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Securities	5		27			5
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value [Abstract]
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value	8,550		647,058			8,550
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value	128,896		0			128,896
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	137,446		647,058			137,446
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Losses [Abstract]
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	12		8,532			12
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	2,605		0			2,605
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss	2,617		8,532			2,617
Other than Temporary Impairment Losses, Investments, Available-for-sale Securities, Portion Recognized In Earnings, Net Qualitative Disclosures, Lowest Current Credit Rating [Abstract]
Available-for-sale Securities, Portfolio Concentration US Govt or GSE Securities Not Rated, Amortized Cost	801,820	[3]				801,820	[3]
Available-for-sale Securities, Portfolio Concentration US Govt or GSE Securities Not Rated, Fair Value	807,443	[3]				807,443	[3]
Available-for-sale securities, Portfolio Concentration Rated AAA To AA, Amortized Cost	0					0
Available-for-sale Securities, Portfolio Concentration Rated AAA To AA, Fair Value	0					0
Available-for-sale Securities, Portfolio Concentration Rated A To BBB, Amortized Cost	0					0
Available-for-sale Securities, Portfolio Concentration Rated A To BBB, Fair Value	0					0
Available-for-sale Securities, Portfolio Concentration Rated Below Investment Grade, Amortized Cost	0					0
Available-for-sale Securities, Portfolio Concentration Rated Below Investment Grade, Fair Value	0					0
Available-for-sale Securities, Portfolio Concentration Not Rated, Amortized Cost	0					0
Available-for-sale Securities, Portfolio Concentration Not Rated, Fair Value	0					0
U.S. government agency residential mortgage-backed securities [Member] | Other [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Amortized Cost	4,808		36,296			4,808
Available-for-sale Securities, Fair Value	5,143		37,607			5,143
Available-for-sale Securities, Gross Unrealized Gain	335	[1]	1,311	[1]		335	[1]
Available-for-sale Securities, Gross Unrealized Loss	0	[1]	0	[1]		0	[1]
Available-for-sale Securities, Other Than Temporary Impairments	0	[2]	0	[2]		0	[2]
Other than Temporary Impairment Losses, Investments, Available-for-sale Securities, Portion Recognized In Earnings, Net Qualitative Disclosures, Lowest Current Credit Rating [Abstract]
Available-for-sale Securities, Portfolio Concentration US Govt or GSE Securities Not Rated, Amortized Cost	4,808	[3]				4,808	[3]
Available-for-sale Securities, Portfolio Concentration US Govt or GSE Securities Not Rated, Fair Value	5,143	[3]				5,143	[3]
Available-for-sale securities, Portfolio Concentration Rated AAA To AA, Amortized Cost	0					0
Available-for-sale Securities, Portfolio Concentration Rated AAA To AA, Fair Value	0					0
Available-for-sale Securities, Portfolio Concentration Rated A To BBB, Amortized Cost	0					0
Available-for-sale Securities, Portfolio Concentration Rated A To BBB, Fair Value	0					0
Available-for-sale Securities, Portfolio Concentration Rated Below Investment Grade, Amortized Cost	0					0
Available-for-sale Securities, Portfolio Concentration Rated Below Investment Grade, Fair Value	0					0
Available-for-sale Securities, Portfolio Concentration Not Rated, Amortized Cost	0					0
Available-for-sale Securities, Portfolio Concentration Not Rated, Fair Value	0					0
Privately issued residential mortgage-backed securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Amortized Cost	154,360		214,181			154,360
Available-for-sale Securities, Fair Value	165,957		221,099			165,957
Available-for-sale Securities, Gross Unrealized Gain	12,261	[1]	9,360	[1]		12,261	[1]
Available-for-sale Securities, Gross Unrealized Loss	0	[1]	0	[1]		0	[1]
Available-for-sale Securities, Other Than Temporary Impairments	(664)	[2]	(2,442)	[2]		(664)	[2]
Available-for-sale Securities, Continuous Unrealized Loss Position, Qualitative Disclosure [Abstract]
Available-for-sale, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Securities	12	[8]	16	[8]		12	[8]
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value [Abstract]
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value	11,277	[8]	25,685	[8]		11,277	[8]
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value	10,020	[8]	30,774	[8]		10,020	[8]
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	21,297	[8]	56,459	[8]		21,297	[8]
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Losses [Abstract]
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	307	[8]	1,465	[8]		307	[8]
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	357	[8]	977	[8]		357	[8]
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss	664	[8]	2,442	[8]		664	[8]
Other than Temporary Impairment Losses, Investments, Available-for-sale Securities, Portion Recognized In Earnings, Net Qualitative Disclosures, Lowest Current Credit Rating [Abstract]
Available-for-sale Securities, Portfolio Concentration US Govt or GSE Securities Not Rated, Amortized Cost	0	[3]				0	[3]
Available-for-sale Securities, Portfolio Concentration US Govt or GSE Securities Not Rated, Fair Value	0	[3]				0	[3]
Available-for-sale securities, Portfolio Concentration Rated AAA To AA, Amortized Cost	0					0
Available-for-sale Securities, Portfolio Concentration Rated AAA To AA, Fair Value	0					0
Available-for-sale Securities, Portfolio Concentration Rated A To BBB, Amortized Cost	0					0
Available-for-sale Securities, Portfolio Concentration Rated A To BBB, Fair Value	0					0
Available-for-sale Securities, Portfolio Concentration Rated Below Investment Grade, Amortized Cost	154,360					154,360
Available-for-sale Securities, Portfolio Concentration Rated Below Investment Grade, Fair Value	165,957					165,957
Available-for-sale Securities, Portfolio Concentration Not Rated, Amortized Cost	0					0
Available-for-sale Securities, Portfolio Concentration Not Rated, Fair Value	0					0
Other Than Temporary Impairment Losses, Investments, Available-for-sale Securities, Portion Recognized in Earnings, Net, Qualitative Disclosures, Assumptions Used to Develop Projected Cash Flows [Abstract]
Unemployment rate	Held constant at 5.6% over the next 12 months and remain at 5.6% thereafter.		Increasing to 7.3% over the next 12 months and remain at 7.3% thereafter
Housing price appreciation/depreciation	Starting with current depreciated housing prices based on information derived from the FHFA1, appreciating 3.2% over the next 12 months, then flat for the following 12 months and then appreciating at 2% per year thereafter.	[9]	Starting with current depreciated housing prices based on information derived from the FHFA1, appreciating 4% over the next 12 months, then flat for the following 12 months and then appreciating at 2% per year thereafter.	[9]
Estimated liquidation costs	Reflect actual historical liquidations costs observed on Jumbo and Alt-A residential mortgage loans in securities owned by the Company.		Reflect actual historical liquidations costs observed on Jumbo and Alt-A residential mortgage loans in securities owned by the Company.
Discount rates	Estimated cash flows were discounted at rates that range from 2.00% to 6.25% based on our current expected yields.		Estimated cash flows were discounted at rates that range from 2.00% to 6.25% based on our current expected yields.
Available-for-sale Securities, Privately Issued Residential Mortgage-backed Securities, Number of Securities	44					44
Available-for-sale Securities, Privately Issued Residential Mortgage-backed Securities, Number of Securities with Credit Losses	0					43
Available-for-sale Securities, Other than Temporary Impairment Losses, Credit Losses Recognized	0		938		5,900	54,347
Privately issued residential mortgage-backed securities [Member] | Alt A loans [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Amortized Cost	65,582		104,559			65,582
Available-for-sale Securities, Fair Value	71,952		107,212			71,952
Available-for-sale Securities, Gross Unrealized Gain	6,677	[1]	4,386	[1]		6,677	[1]
Available-for-sale Securities, Gross Unrealized Loss	0	[1]	0	[1]		0	[1]
Available-for-sale Securities, Other Than Temporary Impairments	(307)	[2]	(1,733)	[2]		(307)	[2]
Available-for-sale Securities, Continuous Unrealized Loss Position, Qualitative Disclosure [Abstract]
Available-for-sale, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Securities	4	[8]	7	[8]		4	[8]
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value [Abstract]
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value	11,277	[8]	11,043	[8]		11,277	[8]
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value	0	[8]	30,774	[8]		0	[8]
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	11,277	[8]	41,817	[8]		11,277	[8]
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Losses [Abstract]
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	307	[8]	756	[8]		307	[8]
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	0	[8]	977	[8]		0	[8]
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss	307	[8]	1,733	[8]		307	[8]
Other than Temporary Impairment Losses, Investments, Available-for-sale Securities, Portion Recognized In Earnings, Net Qualitative Disclosures, Lowest Current Credit Rating [Abstract]
Available-for-sale Securities, Portfolio Concentration US Govt or GSE Securities Not Rated, Amortized Cost	0	[3]				0	[3]
Available-for-sale Securities, Portfolio Concentration US Govt or GSE Securities Not Rated, Fair Value	0	[3]				0	[3]
Available-for-sale securities, Portfolio Concentration Rated AAA To AA, Amortized Cost	0					0
Available-for-sale Securities, Portfolio Concentration Rated AAA To AA, Fair Value	0					0
Available-for-sale Securities, Portfolio Concentration Rated A To BBB, Amortized Cost	0					0
Available-for-sale Securities, Portfolio Concentration Rated A To BBB, Fair Value	0					0
Available-for-sale Securities, Portfolio Concentration Rated Below Investment Grade, Amortized Cost	65,582					65,582
Available-for-sale Securities, Portfolio Concentration Rated Below Investment Grade, Fair Value	71,952					71,952
Available-for-sale Securities, Portfolio Concentration Not Rated, Amortized Cost	0					0
Available-for-sale Securities, Portfolio Concentration Not Rated, Fair Value	0					0
Other Than Temporary Impairment Losses, Investments, Available-for-sale Securities, Portion Recognized in Earnings, Net, Qualitative Disclosures, Assumptions Used to Develop Projected Cash Flows [Abstract]
Available-for-sale Securities, Privately Issued Residential Mortgage-backed Securities, Number of Securities	14					14
Available-for-sale Securities, Privately Issued Residential Mortgage-backed Securities, Number of Securities with Credit Losses	0					14
Available-for-sale Securities, Other than Temporary Impairment Losses, Credit Losses Recognized	0					36,127
Privately issued residential mortgage-backed securities [Member] | Jumbo A Loans [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Amortized Cost	88,778		109,622			88,778
Available-for-sale Securities, Fair Value	94,005		113,887			94,005
Available-for-sale Securities, Gross Unrealized Gain	5,584	[1]	4,974	[1]		5,584	[1]
Available-for-sale Securities, Gross Unrealized Loss	0	[1]	0	[1]		0	[1]
Available-for-sale Securities, Other Than Temporary Impairments	(357)	[2]	(709)	[2]		(357)	[2]
Available-for-sale Securities, Continuous Unrealized Loss Position, Qualitative Disclosure [Abstract]
Available-for-sale, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Securities	8	[8]	9	[8]		8	[8]
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value [Abstract]
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value	0	[8]	14,642	[8]		0	[8]
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value	10,020	[8]	0	[8]		10,020	[8]
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	10,020	[8]	14,642	[8]		10,020	[8]
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Losses [Abstract]
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	0	[8]	709	[8]		0	[8]
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	357	[8]	0	[8]		357	[8]
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss	357	[8]	709	[8]		357	[8]
Other than Temporary Impairment Losses, Investments, Available-for-sale Securities, Portion Recognized In Earnings, Net Qualitative Disclosures, Lowest Current Credit Rating [Abstract]
Available-for-sale Securities, Portfolio Concentration US Govt or GSE Securities Not Rated, Amortized Cost	0	[3]				0	[3]
Available-for-sale Securities, Portfolio Concentration US Govt or GSE Securities Not Rated, Fair Value	0	[3]				0	[3]
Available-for-sale securities, Portfolio Concentration Rated AAA To AA, Amortized Cost	0					0
Available-for-sale Securities, Portfolio Concentration Rated AAA To AA, Fair Value	0					0
Available-for-sale Securities, Portfolio Concentration Rated A To BBB, Amortized Cost	0					0
Available-for-sale Securities, Portfolio Concentration Rated A To BBB, Fair Value	0					0
Available-for-sale Securities, Portfolio Concentration Rated Below Investment Grade, Amortized Cost	88,778					88,778
Available-for-sale Securities, Portfolio Concentration Rated Below Investment Grade, Fair Value	94,005					94,005
Available-for-sale Securities, Portfolio Concentration Not Rated, Amortized Cost	0					0
Available-for-sale Securities, Portfolio Concentration Not Rated, Fair Value	0					0
Other Than Temporary Impairment Losses, Investments, Available-for-sale Securities, Portion Recognized in Earnings, Net, Qualitative Disclosures, Assumptions Used to Develop Projected Cash Flows [Abstract]
Available-for-sale Securities, Privately Issued Residential Mortgage-backed Securities, Number of Securities	30					30
Available-for-sale Securities, Privately Issued Residential Mortgage-backed Securities, Number of Securities with Credit Losses	0					29
Available-for-sale Securities, Other than Temporary Impairment Losses, Credit Losses Recognized	0					18,220
Perpetual preferred stock, equity securities and mutual funds [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Amortized Cost	40,774					40,774
Available-for-sale Securities, Fair Value	43,721					43,721
Available-for-sale Securities, Debt Maturities, Nominal Yield [Abstract]
Available-for-sale Securities, Debt Maturities, Nominal Yield	1.28%					1.28%
Perpetual preferred stock [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Amortized Cost	22,171		22,171			22,171
Available-for-sale Securities, Fair Value	24,277		22,863			24,277
Available-for-sale Securities, Gross Unrealized Gain	2,183	[1]	705	[1]		2,183	[1]
Available-for-sale Securities, Gross Unrealized Loss	(77)	[1]	(13)	[1]		(77)	[1]
Available-for-sale Securities, Other Than Temporary Impairments	0	[2]	0	[2]		0	[2]
Available-for-sale Securities, Continuous Unrealized Loss Position, Qualitative Disclosure [Abstract]
Available-for-sale, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Securities	2		1			2
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value [Abstract]
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value	2,898		4,988			2,898
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value	0		0			0
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	2,898		4,988			2,898
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Losses [Abstract]
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	77		13			77
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	0		0			0
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss	77		13			77
Other than Temporary Impairment Losses, Investments, Available-for-sale Securities, Portion Recognized In Earnings, Net Qualitative Disclosures, Lowest Current Credit Rating [Abstract]
Available-for-sale Securities, Portfolio Concentration US Govt or GSE Securities Not Rated, Amortized Cost	0	[3]				0	[3]
Available-for-sale Securities, Portfolio Concentration US Govt or GSE Securities Not Rated, Fair Value	0	[3]				0	[3]
Available-for-sale securities, Portfolio Concentration Rated AAA To AA, Amortized Cost	0					0
Available-for-sale Securities, Portfolio Concentration Rated AAA To AA, Fair Value	0					0
Available-for-sale Securities, Portfolio Concentration Rated A To BBB, Amortized Cost	11,406					11,406
Available-for-sale Securities, Portfolio Concentration Rated A To BBB, Fair Value	12,508					12,508
Available-for-sale Securities, Portfolio Concentration Rated Below Investment Grade, Amortized Cost	10,765					10,765
Available-for-sale Securities, Portfolio Concentration Rated Below Investment Grade, Fair Value	11,769					11,769
Available-for-sale Securities, Portfolio Concentration Not Rated, Amortized Cost	0					0
Available-for-sale Securities, Portfolio Concentration Not Rated, Fair Value	0					0
Equity securities and mutual funds [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Amortized Cost	18,603		19,069			18,603
Available-for-sale Securities, Fair Value	19,444		21,328			19,444
Available-for-sale Securities, Gross Unrealized Gain	871	[1]	2,326	[1]		871	[1]
Available-for-sale Securities, Gross Unrealized Loss	(30)	[1]	(67)	[1]		(30)	[1]
Available-for-sale Securities, Other Than Temporary Impairments	0	[2]	0	[2]		0	[2]
Available-for-sale Securities, Continuous Unrealized Loss Position, Qualitative Disclosure [Abstract]
Available-for-sale, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Securities	68		118			68
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value [Abstract]
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value	0		2,070			0
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value	1,205		0			1,205
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	1,205		2,070			1,205
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Losses [Abstract]
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	0		67			0
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	30		0			30
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss	30		67			30
Other than Temporary Impairment Losses, Investments, Available-for-sale Securities, Portion Recognized In Earnings, Net Qualitative Disclosures, Lowest Current Credit Rating [Abstract]
Available-for-sale Securities, Portfolio Concentration US Govt or GSE Securities Not Rated, Amortized Cost	0	[3]				0	[3]
Available-for-sale Securities, Portfolio Concentration US Govt or GSE Securities Not Rated, Fair Value	0	[3]				0	[3]
Available-for-sale securities, Portfolio Concentration Rated AAA To AA, Amortized Cost	4					4
Available-for-sale Securities, Portfolio Concentration Rated AAA To AA, Fair Value	517					517
Available-for-sale Securities, Portfolio Concentration Rated A To BBB, Amortized Cost	0					0
Available-for-sale Securities, Portfolio Concentration Rated A To BBB, Fair Value	0					0
Available-for-sale Securities, Portfolio Concentration Rated Below Investment Grade, Amortized Cost	0					0
Available-for-sale Securities, Portfolio Concentration Rated Below Investment Grade, Fair Value	0					0
Available-for-sale Securities, Portfolio Concentration Not Rated, Amortized Cost	18,599					18,599
Available-for-sale Securities, Portfolio Concentration Not Rated, Fair Value	18,927					18,927
Other Than Temporary Impairment Losses, Investments, Available-for-sale Securities, Portion Recognized in Earnings, Net, Qualitative Disclosures, Assumptions Used to Develop Projected Cash Flows [Abstract]
Available-for-sale Securities, Other than Temporary Impairment Losses, Credit Losses Recognized	$ 373		$ 0		$ 457

[1] Gross unrealized gain/loss recognized in AOCI in the consolidated balance sheet.

[2] Amounts represent unrealized loss that remains in AOCI after an other-than-temporary credit loss has been recognized in income.

[3] 1 U.S. government and government sponsored enterprises are not rated by the nationally-recognized rating agencies as these securities are guaranteed by agencies of the U.S. government or government-sponsored enterprises.

[4] Expected maturities may differ from contractual maturities, because borrowers may have the right to call or prepay obligations with or without penalty.

[5] Calculated on a taxable equivalent basis using a 39% effective tax rate.

[6] Nominal yield on municipal and other tax-exempt securities and other debt securities with contractual maturity dates over ten years are based on variable rates which generally are reset within 35 days.

[7] The nominal yield on mortgage-backed securities is based upon prepayment assumptions at the purchase date. Actual yields earned may differ significantly based upon actual prepayments. See Quarterly Financial Summary –– Unaudited following for current yields on available for sale securities portfolio.

[8] Includes securities for which an unrealized loss remains in AOCI after an other-than-temporary credit loss has been recognized in income.

[9] Federal Housing Finance Agency