Available for Sale Securities (Details) (USD $)	12 Months Ended					60 Months Ended
	Dec. 31, 2013		Dec. 31, 2012		Dec. 31, 2011	Dec. 31, 2013
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Amortized Cost Basis	$ 10,185,091,000		$ 11,032,634,000			$ 10,185,091,000
Available-for-sale Securities, Fair Value	10,147,162,000		11,287,221,000			10,147,162,000
Available-for-sale Securities, Gross Unrealized Gains	120,120,000	[1]	261,184,000	[2]		120,120,000	[1]
Available-for-sale Securities, Gross Unrealized Loss	(155,607,000)	[1]	(2,414,000)	[2]		(155,607,000)	[1]
Available-for-Sale Securities, Other Than Temporary Impairments	(2,442,000)	[3]	(4,183,000)	[3]		(2,442,000)	[3]
Available-for-sale Securities, Debt Maturities, Nominal Yield [Abstract]
Available-for-sale Securities, Debt Maturities, Nominal Yield	1.80%					1.80%
Available-for-sale Securities, Gross Realized Gain (Loss), Disclosures [Abstract]
Available-for-sale Securities, Proceeds	2,436,093,000		1,744,662,000		2,725,760,000
Available-for-sale Securities, Gross realized gains	25,711,000		41,191,000		41,284,000
Available-for-sale Securities, Gross realized losses	(14,991,000)		(7,346,000)		(7,140,000)
Related federal and state income tax expense	4,170,000		13,166,000		13,282,000
Available-for-sale Securities, Pledged as Collateral [Abstract]
Available-for-sale Securities, Pledged As Collateral, Amortized cost	5,171,782,000		4,070,250,000			5,171,782,000
Available-for-sale Securities, Pledged As Collateral, Fair value	5,133,530,000		4,186,390,000			5,133,530,000
Available-for-sale Securities, Continuous Unrealized Loss Position, Qualitative Disclosure [Abstract]
Available-for-sale, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Positions	446		106			446
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	6,230,595,000		448,144,000			6,230,595,000
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value	50,865,000		159,428,000			50,865,000
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	6,281,460,000		607,572,000			6,281,460,000
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	156,172,000		1,850,000			156,172,000
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	1,877,000		4,747,000			1,877,000
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss	158,049,000		6,597,000			158,049,000
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	9,821,377,000	[4]				9,821,377,000	[4]
Available-for-sale Securities, Portfolio Concentration US Govt or GSE Securities Not Rated, Fair Value	9,772,856,000	[4]				9,772,856,000	[4]
Available-for-sale securities, Portfolio Concentration Rated AAA To AA, Amortized Cost	49,873,000					49,873,000
Available-for-sale Securities, Portfolio Concentration Rated AAA To AA, Fair Value	51,153,000					51,153,000
Available-for-sale Securities, Portfolio Concentration Rated A To BBB, Amortized Cost	57,421,000					57,421,000
Available-for-sale Securities, Portfolio Concentration Rated A To BBB, Fair Value	57,933,000					57,933,000
Available-for-sale Securities, Portfolio Concentration Rated Below Investment Grade, Amortized Cost	224,946,000					224,946,000
Available-for-sale Securities, Portfolio Concentration Rated Below Investment Grade, Fair Value	232,103,000					232,103,000
Available-for-sale Securities, Portfolio Concentration Rated Below Investment Grade, Net Unrealized Gain (Loss)	(2,400,000)					(2,400,000)
Available-for-sale Securities, Portfolio Concentration Not Rated, Amortized Cost	31,474,000					31,474,000
Available-for-sale Securities, Portfolio Concentration Not Rated, Fair Value	33,117,000					33,117,000
Fixed Maturity Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Amortized Cost Basis	2,209,481,000					2,209,481,000
Available-for-sale Securities, Fair Value	2,165,862,000					2,165,862,000
Available-for-sale Securities, Debt Maturities, Amortized Cost Basis, Rolling Maturity [Abstract]
Available-for-sale Securities, Debt Maturities, Less than One Year, Amortized Cost Basis	27,890,000					27,890,000
Available-for-sale Securities, Debt Maturities, One to Five Years, Amortized Cost Basis	667,679,000					667,679,000
Available-for-sale Securities, Debt Maturities, Six to Ten Years, Amortized Cost Basis	1,107,334,000					1,107,334,000
Available-for-sale Securities, Debt Maturities, Over Ten Years, Amortized Cost Basis	406,578,000					406,578,000
Available-for-sale Securities, Debt Maturities, Fair Value, Rolling Maturity [Abstract]
Available-for-sale Securities, Debt Maturities, Less Than One Year, Fair Value	28,194,000					28,194,000
Available-for-sale Securities, Debt Maturities, One to Five Years, Fair Value	661,948,000					661,948,000
Available-for-sale Securities, Debt Maturities, Six to Ten Years, Fair Value	1,076,922,000					1,076,922,000
Available-for-sale Securities, Debt Maturities, Over Ten Years, Fair Value	398,798,000					398,798,000
Available-for-sale Securities, Debt Maturities, Nominal Yield [Abstract]
Available-for-sale Securities, Debt Maturities, Less than One Year, Nominal Yield	2.05%					2.05%
Available-for-sale Securities, Debt Maturities, One to Five Years, Nominal Yield	1.37%					1.37%
Available-for-sale Securities, Debt Maturities, Six to Ten Years, Nominal Yield	1.44%					1.44%
Available-for-sale Securities, Debt Maturities, Greater Than Ten Years, Nominal Yield	1.58%					1.58%
Available-for-sale Securities, Debt Maturities, Nominal Yield	1.45%					1.45%
Available-for-sale Securities, Debt Maturities, Weighted Average Maturity	9.38	[5]				9.38	[5]
US Treasury Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Amortized Cost Basis	1,042,000		1,000,000			1,042,000
Available-for-sale Securities, Fair Value	1,042,000		1,002,000			1,042,000
Available-for-sale Securities, Gross Unrealized Gains	0	[1]	2,000	[2]		0	[1]
Available-for-sale Securities, Gross Unrealized Loss	0	[1]	0	[2]		0	[1]
Available-for-Sale Securities, Other Than Temporary Impairments	0	[3]	0	[3]		0	[3]
Available-for-sale Securities, Debt Maturities, Amortized Cost Basis, Rolling Maturity [Abstract]
Available-for-sale Securities, Debt Maturities, Less than One Year, Amortized Cost Basis	1,042,000					1,042,000
Available-for-sale Securities, Debt Maturities, One to Five Years, Amortized Cost Basis	0					0
Available-for-sale Securities, Debt Maturities, Six to Ten Years, Amortized Cost Basis	0					0
Available-for-sale Securities, Debt Maturities, Over Ten Years, Amortized Cost Basis	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	1,042,000					1,042,000
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	1.16	[5]				1.16	[5]
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	1,042,000	[4]				1,042,000	[4]
Available-for-sale Securities, Portfolio Concentration US Govt or GSE Securities Not Rated, Fair Value	1,042,000	[4]				1,042,000	[4]
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 Basis	73,232,000		84,892,000			73,232,000
Available-for-sale Securities, Fair Value	73,775,000		87,142,000			73,775,000
Available-for-sale Securities, Gross Unrealized Gains	1,606,000	[1]	2,414,000	[2]		1,606,000	[1]
Available-for-sale Securities, Gross Unrealized Loss	(1,063,000)	[1]	(164,000)	[2]		(1,063,000)	[1]
Available-for-Sale Securities, Other Than Temporary Impairments	0	[3]	0	[3]		0	[3]
Available-for-sale Securities, Debt Maturities, Amortized Cost Basis, Rolling Maturity [Abstract]
Available-for-sale Securities, Debt Maturities, Less than One Year, Amortized Cost Basis	1,856,000					1,856,000
Available-for-sale Securities, Debt Maturities, One to Five Years, Amortized Cost Basis	36,183,000					36,183,000
Available-for-sale Securities, Debt Maturities, Six to Ten Years, Amortized Cost Basis	3,239,000					3,239,000
Available-for-sale Securities, Debt Maturities, Over Ten Years, Amortized Cost Basis	31,954,000					31,954,000
Available-for-sale Securities, Debt Maturities, Fair Value, Rolling Maturity [Abstract]
Available-for-sale Securities, Debt Maturities, Less Than One Year, Fair Value	1,882,000					1,882,000
Available-for-sale Securities, Debt Maturities, One to Five Years, Fair Value	37,470,000					37,470,000
Available-for-sale Securities, Debt Maturities, Six to Ten Years, Fair Value	3,451,000					3,451,000
Available-for-sale Securities, Debt Maturities, Over Ten Years, Fair Value	30,972,000					30,972,000
Available-for-sale Securities, Debt Maturities, Nominal Yield [Abstract]
Available-for-sale Securities, Debt Maturities, Less than One Year, Nominal Yield	6.35%	[6]				6.35%	[6]
Available-for-sale Securities, Debt Maturities, One to Five Years, Nominal Yield	3.84%	[6]				3.84%	[6]
Available-for-sale Securities, Debt Maturities, Six to Ten Years, Nominal Yield	6.34%	[6]				6.34%	[6]
Available-for-sale Securities, Debt Maturities, Greater Than Ten Years, Nominal Yield	5.41%	[6],[7]				5.41%	[6],[7]
Available-for-sale Securities, Debt Maturities, Nominal Yield	4.70%	[6]				4.70%	[6]
Available-for-sale Securities, Debt Maturities, Weighted Average Maturity	10.48	[5]				10.48	[5]
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					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 Positions	27		38			27
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	13,286,000		6,150,000			13,286,000
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value	17,805,000		26,108,000			17,805,000
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	31,091,000		32,258,000			31,091,000
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	245,000		11,000			245,000
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	818,000		153,000			818,000
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss	1,063,000		164,000			1,063,000
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	[4]				0	[4]
Available-for-sale Securities, Portfolio Concentration US Govt or GSE Securities Not Rated, Fair Value	0	[4]				0	[4]
Available-for-sale securities, Portfolio Concentration Rated AAA To AA, Amortized Cost	44,969,000					44,969,000
Available-for-sale Securities, Portfolio Concentration Rated AAA To AA, Fair Value	45,984,000					45,984,000
Available-for-sale Securities, Portfolio Concentration Rated A To BBB, Amortized Cost	15,854,000					15,854,000
Available-for-sale Securities, Portfolio Concentration Rated A To BBB, Fair Value	15,545,000					15,545,000
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	12,409,000					12,409,000
Available-for-sale Securities, Portfolio Concentration Not Rated, Fair Value	12,246,000					12,246,000
Available-for-sale Securities, Privately Issued Residential Mortgage-backed Securities, Credit losses Recognized [Abstract]
Amount of Credit Losses Recognized in Current Period	(1,400,000)		(1,000,000)		(1,600,000)
Commercial mortgage-backed securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Amortized Cost Basis	2,100,146,000		890,746,000			2,100,146,000
Available-for-sale Securities, Fair Value	2,055,804,000		895,075,000			2,055,804,000
Available-for-sale Securities, Gross Unrealized Gains	1,042,000	[1]	5,006,000	[2]		1,042,000	[1]
Available-for-sale Securities, Gross Unrealized Loss	(45,384,000)	[1]	(677,000)	[2]		(45,384,000)	[1]
Available-for-Sale Securities, Other Than Temporary Impairments	0	[3]	0	[3]		0	[3]
Available-for-sale Securities, Debt Maturities, Amortized Cost Basis, Rolling Maturity [Abstract]
Available-for-sale Securities, Debt Maturities, Less than One Year, Amortized Cost Basis	0					0
Available-for-sale Securities, Debt Maturities, One to Five Years, Amortized Cost Basis	626,327,000					626,327,000
Available-for-sale Securities, Debt Maturities, Six to Ten Years, Amortized Cost Basis	1,104,095,000					1,104,095,000
Available-for-sale Securities, Debt Maturities, Over Ten Years, Amortized Cost Basis	369,724,000					369,724,000
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	619,219,000					619,219,000
Available-for-sale Securities, Debt Maturities, Six to Ten Years, Fair Value	1,073,471,000					1,073,471,000
Available-for-sale Securities, Debt Maturities, Over Ten Years, Fair Value	363,114,000					363,114,000
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	1.22%					1.22%
Available-for-sale Securities, Debt Maturities, Six to Ten Years, Nominal Yield	1.43%					1.43%
Available-for-sale Securities, Debt Maturities, Greater Than Ten Years, Nominal Yield	1.25%					1.25%
Available-for-sale Securities, Debt Maturities, Nominal Yield	1.34%					1.34%
Available-for-sale Securities, Debt Maturities, Weighted Average Maturity	9.41	[5]				9.41	[5]
Available-for-sale Securities, Continuous Unrealized Loss Position, Qualitative Disclosure [Abstract]
Available-for-sale, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Positions	123		8			123
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	1,800,717,000		275,065,000			1,800,717,000
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value	2,286,000		0			2,286,000
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	1,803,003,000		275,065,000			1,803,003,000
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	45,302,000		677,000			45,302,000
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	82,000		0			82,000
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss	45,384,000		677,000			45,384,000
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	2,100,146,000	[4]				2,100,146,000	[4]
Available-for-sale Securities, Portfolio Concentration US Govt or GSE Securities Not Rated, Fair Value	2,055,804,000	[4]				2,055,804,000	[4]
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 Basis	35,061,000		35,680,000			35,061,000
Available-for-sale Securities, Fair Value	35,241,000		36,389,000			35,241,000
Available-for-sale Securities, Gross Unrealized Gains	368,000	[1]	709,000	[2]		368,000	[1]
Available-for-sale Securities, Gross Unrealized Loss	(188,000)	[1]	0	[2]		(188,000)	[1]
Available-for-Sale Securities, Other Than Temporary Impairments	0	[3]	0	[3]		0	[3]
Available-for-sale Securities, Debt Maturities, Amortized Cost Basis, Rolling Maturity [Abstract]
Available-for-sale Securities, Debt Maturities, Less than One Year, Amortized Cost Basis	24,992,000					24,992,000
Available-for-sale Securities, Debt Maturities, One to Five Years, Amortized Cost Basis	5,169,000					5,169,000
Available-for-sale Securities, Debt Maturities, Six to Ten Years, Amortized Cost Basis	0					0
Available-for-sale Securities, Debt Maturities, Over Ten Years, Amortized Cost Basis	4,900,000					4,900,000
Available-for-sale Securities, Debt Maturities, Fair Value, Rolling Maturity [Abstract]
Available-for-sale Securities, Debt Maturities, Less Than One Year, Fair Value	25,270,000					25,270,000
Available-for-sale Securities, Debt Maturities, One to Five Years, Fair Value	5,259,000					5,259,000
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	4,712,000					4,712,000
Available-for-sale Securities, Debt Maturities, Nominal Yield [Abstract]
Available-for-sale Securities, Debt Maturities, Less than One Year, Nominal Yield	1.74%					1.74%
Available-for-sale Securities, Debt Maturities, One to Five Years, Nominal Yield	2.12%					2.12%
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	1.54%					1.54%
Available-for-sale Securities, Debt Maturities, Nominal Yield	1.77%					1.77%
Available-for-sale Securities, Debt Maturities, Weighted Average Maturity	5.31	[5]				5.31	[5]
Available-for-sale Securities, Continuous Unrealized Loss Position, Qualitative Disclosure [Abstract]
Available-for-sale, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Positions	3		3			3
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	4,712,000		4,899,000			4,712,000
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	4,712,000		4,899,000			4,712,000
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	188,000		0			188,000
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	188,000		0			188,000
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	[4]				0	[4]
Available-for-sale Securities, Portfolio Concentration US Govt or GSE Securities Not Rated, Fair Value	0	[4]				0	[4]
Available-for-sale securities, Portfolio Concentration Rated AAA To AA, Amortized Cost	4,900,000					4,900,000
Available-for-sale Securities, Portfolio Concentration Rated AAA To AA, Fair Value	4,712,000					4,712,000
Available-for-sale Securities, Portfolio Concentration Rated A To BBB, Amortized Cost	30,161,000					30,161,000
Available-for-sale Securities, Portfolio Concentration Rated A To BBB, Fair Value	30,529,000					30,529,000
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 Basis	7,934,370,000		9,973,552,000			7,934,370,000
Available-for-sale Securities, Fair Value	7,937,109,000		10,214,984,000			7,937,109,000
Available-for-sale Securities, Gross Unrealized Gains	114,073,000	[1]	246,910,000	[2]		114,073,000	[1]
Available-for-sale Securities, Gross Unrealized Loss	(108,892,000)	[1]	(1,295,000)	[2]		(108,892,000)	[1]
Available-for-Sale Securities, Other Than Temporary Impairments	(2,442,000)	[3]	(4,183,000)	[3]		(2,442,000)	[3]
Available-for-sale Securities, Debt Maturities, Nominal Yield [Abstract]
Available-for-sale Securities, Debt Maturities, Nominal Yield	1.90%	[8]				1.90%	[8]
Available-for-sale Securities, Debt Maturities, Average Expected Life of Mortgage-backed Securities	3 years 110 days					3 years 110 days
Available-for-sale Securities, Continuous Unrealized Loss Position, Qualitative Disclosure [Abstract]
Available-for-sale, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Positions	174		35			174
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	4,404,822,000		161,828,000			4,404,822,000
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value	30,774,000		131,159,000			30,774,000
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	4,435,596,000		292,987,000			4,435,596,000
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	110,357,000		1,161,000			110,357,000
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	977,000		4,317,000			977,000
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss	111,334,000		5,478,000			111,334,000
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	7,720,189,000	[4]				7,720,189,000	[4]
Available-for-sale Securities, Portfolio Concentration US Govt or GSE Securities Not Rated, Fair Value	7,716,010,000	[4]				7,716,010,000	[4]
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	214,181,000					214,181,000
Available-for-sale Securities, Portfolio Concentration Rated Below Investment Grade, Fair Value	221,099,000					221,099,000
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. agency residential mortgage-backed securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Amortized Cost Basis	7,720,189,000		9,650,650,000			7,720,189,000
Available-for-sale Securities, Fair Value	7,716,010,000		9,889,821,000			7,716,010,000
Available-for-sale Securities, Gross Unrealized Gains	104,713,000	[1]	240,332,000	[2]		104,713,000	[1]
Available-for-sale Securities, Gross Unrealized Loss	(108,892,000)	[1]	(1,161,000)	[2]		(108,892,000)	[1]
Available-for-Sale Securities, Other Than Temporary Impairments	0	[3]	0	[3]		0	[3]
Available-for-sale Securities, Continuous Unrealized Loss Position, Qualitative Disclosure [Abstract]
Available-for-sale, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Positions	158		12			158
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	4,379,137,000		161,828,000			4,379,137,000
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	4,379,137,000		161,828,000			4,379,137,000
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	108,892,000		1,161,000			108,892,000
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	108,892,000		1,161,000			108,892,000
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	7,720,189,000	[4]				7,720,189,000	[4]
Available-for-sale Securities, Portfolio Concentration US Govt or GSE Securities Not Rated, Fair Value	7,716,010,000	[4]				7,716,010,000	[4]
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. 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 Basis	4,224,327,000		5,308,463,000			4,224,327,000
Available-for-sale Securities, Fair Value	4,232,332,000		5,453,549,000			4,232,332,000
Available-for-sale Securities, Gross Unrealized Gains	68,154,000	[1]	146,247,000	[2]		68,154,000	[1]
Available-for-sale Securities, Gross Unrealized Loss	(60,149,000)	[1]	(1,161,000)	[2]		(60,149,000)	[1]
Available-for-Sale Securities, Other Than Temporary Impairments	0	[3]	0	[3]		0	[3]
Available-for-sale Securities, Continuous Unrealized Loss Position, Qualitative Disclosure [Abstract]
Available-for-sale, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Positions	81		12			81
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	2,281,491,000		161,828,000			2,281,491,000
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	2,281,491,000		161,828,000			2,281,491,000
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	60,149,000		1,161,000			60,149,000
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	60,149,000		1,161,000			60,149,000
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	4,224,327,000	[4]				4,224,327,000	[4]
Available-for-sale Securities, Portfolio Concentration US Govt or GSE Securities Not Rated, Fair Value	4,232,332,000	[4]				4,232,332,000	[4]
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. 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 Basis	2,308,341,000		2,978,608,000			2,308,341,000
Available-for-sale Securities, Fair Value	2,293,943,000		3,045,564,000			2,293,943,000
Available-for-sale Securities, Gross Unrealized Gains	25,813,000	[1]	66,956,000	[2]		25,813,000	[1]
Available-for-sale Securities, Gross Unrealized Loss	(40,211,000)	[1]	0	[2]		(40,211,000)	[1]
Available-for-Sale Securities, Other Than Temporary Impairments	0	[3]	0	[3]		0	[3]
Available-for-sale Securities, Continuous Unrealized Loss Position, Qualitative Disclosure [Abstract]
Available-for-sale, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Positions	50		0			50
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	1,450,588,000		0			1,450,588,000
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	1,450,588,000		0			1,450,588,000
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	40,211,000		0			40,211,000
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	40,211,000		0			40,211,000
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	2,308,341,000	[4]				2,308,341,000	[4]
Available-for-sale Securities, Portfolio Concentration US Govt or GSE Securities Not Rated, Fair Value	2,293,943,000	[4]				2,293,943,000	[4]
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. 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 Basis	1,151,225,000		1,215,554,000			1,151,225,000
Available-for-sale Securities, Fair Value	1,152,128,000		1,237,041,000			1,152,128,000
Available-for-sale Securities, Gross Unrealized Gains	9,435,000	[1]	21,487,000	[2]		9,435,000	[1]
Available-for-sale Securities, Gross Unrealized Loss	(8,532,000)	[1]	0	[2]		(8,532,000)	[1]
Available-for-Sale Securities, Other Than Temporary Impairments	0	[3]	0	[3]		0	[3]
Available-for-sale Securities, Continuous Unrealized Loss Position, Qualitative Disclosure [Abstract]
Available-for-sale, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Positions	27		0			27
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	647,058,000		0			647,058,000
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	647,058,000		0			647,058,000
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	8,532,000		0			8,532,000
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	8,532,000		0			8,532,000
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	1,151,225,000	[4]				1,151,225,000	[4]
Available-for-sale Securities, Portfolio Concentration US Govt or GSE Securities Not Rated, Fair Value	1,152,128,000	[4]				1,152,128,000	[4]
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. agency residential mortgage-backed securities [Member] | Other [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Amortized Cost Basis	36,296,000		148,025,000			36,296,000
Available-for-sale Securities, Fair Value	37,607,000		153,667,000			37,607,000
Available-for-sale Securities, Gross Unrealized Gains	1,311,000	[1]	5,642,000	[2]		1,311,000	[1]
Available-for-sale Securities, Gross Unrealized Loss	0	[1]	0	[2]		0	[1]
Available-for-Sale Securities, Other Than Temporary Impairments	0	[3]	0	[3]		0	[3]
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	36,296,000	[4]				36,296,000	[4]
Available-for-sale Securities, Portfolio Concentration US Govt or GSE Securities Not Rated, Fair Value	37,607,000	[4]				37,607,000	[4]
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 Basis	214,181,000		322,902,000			214,181,000
Available-for-sale Securities, Fair Value	221,099,000		325,163,000			221,099,000
Available-for-sale Securities, Gross Unrealized Gains	9,360,000	[1]	6,578,000	[2]		9,360,000	[1]
Available-for-sale Securities, Gross Unrealized Loss	0	[1]	(134,000)	[2]		0	[1]
Available-for-Sale Securities, Other Than Temporary Impairments	(2,442,000)	[3]	(4,183,000)	[3]		(2,442,000)	[3]
Available-for-sale Securities, Continuous Unrealized Loss Position, Qualitative Disclosure [Abstract]
Available-for-sale, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Positions	16	[9]	23	[10]		16	[9]
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	25,685,000	[9]	0	[10]		25,685,000	[9]
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value	30,774,000	[9]	131,159,000	[10]		30,774,000	[9]
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	56,459,000	[9]	131,159,000	[10]		56,459,000	[9]
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	1,465,000	[9]	0	[10]		1,465,000	[9]
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	977,000	[9]	4,317,000	[10]		977,000	[9]
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss	2,442,000	[9]	4,317,000	[10]		2,442,000	[9]
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	[4]				0	[4]
Available-for-sale Securities, Portfolio Concentration US Govt or GSE Securities Not Rated, Fair Value	0	[4]				0	[4]
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	214,181,000					214,181,000
Available-for-sale Securities, Portfolio Concentration Rated Below Investment Grade, Fair Value	221,099,000					221,099,000
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	Increasing to 7.3% over the next 12 months and remain at 7.3% thereafter		Increasing to 8.5% over the next 12 months, dropping to 8% over the following 21 months and holding at 8% thereafter.
Housing price appreciation/depreciation	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.	[11]	Starting with current depreciated housing prices based on information derived from the FHFA1, depreciating 2% over the next 12 months, then flat for the following 12 months and then appreciating at 2% per year thereafter.	[11]
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.
Other than Temporary Impairment Losses, Investments, Available-for-sale Securities, Portion Recognized in Earnings, Net Qualitative Disclosures, Privately Issued Mortgage-backed Securities [Abstract]
Available-for-sale Securities, Privately Issued Residential Mortgage-backed Securities, Number of Securities	47					47
Available-for-sale Securities, Privately Issued Residential Mortgage-backed Securities, Credit losses Recognized [Abstract]
Available-for-sale Securities, Privately Issued Residential Mortgage-backed Securities, Number of Securities with Credit Losses In Current Period	4					45
Amount of Credit Losses Recognized in Current Period	938,000		(5,900,000)		(21,900,000)	67,346,000
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 Basis	104,559,000		124,314,000			104,559,000
Available-for-sale Securities, Fair Value	107,212,000		123,174,000			107,212,000
Available-for-sale Securities, Gross Unrealized Gains	4,386,000	[1]	1,440,000	[2]		4,386,000	[1]
Available-for-sale Securities, Gross Unrealized Loss	0	[1]	0	[2]		0	[1]
Available-for-Sale Securities, Other Than Temporary Impairments	(1,733,000)	[3]	(2,580,000)	[3]		(1,733,000)	[3]
Available-for-sale Securities, Continuous Unrealized Loss Position, Qualitative Disclosure [Abstract]
Available-for-sale, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Positions	7	[9]	12	[10]		7	[9]
Available-for-sale, Securities in Unrealized Loss Positions, Qualitative Disclosure, OTTI Portion, Number of Positions	7		12			7
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	11,043,000	[9]	0	[10]		11,043,000	[9]
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value	30,774,000	[9]	87,907,000	[10]		30,774,000	[9]
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	41,817,000	[9]	87,907,000	[10]		41,817,000	[9]
Available-for-sale Securities, Continuous Unrealized Loss Position, Less Than Twelve Months, OTTI Portion, Fair Value	11,043,000		0			11,043,000
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, OTTI Portion, Fair Value	30,774,000		87,907,000			30,774,000
Available-for-sale Securities, Continuous Unrealized Loss Position, OTTI Portion, Fair Value	41,817,000		87,907,000			41,817,000
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	756,000	[9]	0	[10]		756,000	[9]
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	977,000	[9]	2,580,000	[10]		977,000	[9]
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss	1,733,000	[9]	2,580,000	[10]		1,733,000	[9]
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Losses	756,000		0			756,000
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, OTTI Portion, Accumulated Losses	977,000		2,580,000			977,000
Available-for-sale Securities, Continuous Unrealized Loss Position, OTTI Portion, Accumulated Losses	1,733,000		2,580,000			1,733,000
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	[4]				0	[4]
Available-for-sale Securities, Portfolio Concentration US Govt or GSE Securities Not Rated, Fair Value	0	[4]				0	[4]
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	104,559,000					104,559,000
Available-for-sale Securities, Portfolio Concentration Rated Below Investment Grade, Fair Value	107,212,000					107,212,000
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, Privately Issued Mortgage-backed Securities [Abstract]
Available-for-sale Securities, Privately Issued Residential Mortgage-backed Securities, Number of Securities	16					16
Available-for-sale Securities, Privately Issued Residential Mortgage-backed Securities, Credit losses Recognized [Abstract]
Available-for-sale Securities, Privately Issued Residential Mortgage-backed Securities, Number of Securities with Credit Losses In Current Period	4					16
Amount of Credit Losses Recognized in Current Period	938,000					49,126,000
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 Basis	109,622,000		198,588,000			109,622,000
Available-for-sale Securities, Fair Value	113,887,000		201,989,000			113,887,000
Available-for-sale Securities, Gross Unrealized Gains	4,974,000	[1]	5,138,000	[2]		4,974,000	[1]
Available-for-sale Securities, Gross Unrealized Loss	0	[1]	(134,000)	[2]		0	[1]
Available-for-Sale Securities, Other Than Temporary Impairments	(709,000)	[3]	(1,603,000)	[3]		(709,000)	[3]
Available-for-sale Securities, Continuous Unrealized Loss Position, Qualitative Disclosure [Abstract]
Available-for-sale, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Positions	9	[9]	11	[10]		9	[9]
Available-for-sale, Securities in Unrealized Loss Positions, Qualitative Disclosure, OTTI Portion, Number of Positions	9		10			9
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	14,642,000	[9]	0	[10]		14,642,000	[9]
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value	0	[9]	43,252,000	[10]		0	[9]
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	14,642,000	[9]	43,252,000	[10]		14,642,000	[9]
Available-for-sale Securities, Continuous Unrealized Loss Position, Less Than Twelve Months, OTTI Portion, Fair Value	14,642,000		0			14,642,000
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, OTTI Portion, Fair Value	0		29,128,000			0
Available-for-sale Securities, Continuous Unrealized Loss Position, OTTI Portion, Fair Value	14,642,000		29,128,000			14,642,000
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	709,000	[9]	0	[10]		709,000	[9]
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	0	[9]	1,737,000	[10]		0	[9]
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss	709,000	[9]	1,737,000	[10]		709,000	[9]
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Losses	709,000		0			709,000
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, OTTI Portion, Accumulated Losses	0		1,602,000			0
Available-for-sale Securities, Continuous Unrealized Loss Position, OTTI Portion, Accumulated Losses	709,000		1,602,000			709,000
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	[4]				0	[4]
Available-for-sale Securities, Portfolio Concentration US Govt or GSE Securities Not Rated, Fair Value	0	[4]				0	[4]
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	109,622,000					109,622,000
Available-for-sale Securities, Portfolio Concentration Rated Below Investment Grade, Fair Value	113,887,000					113,887,000
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, Privately Issued Mortgage-backed Securities [Abstract]
Available-for-sale Securities, Privately Issued Residential Mortgage-backed Securities, Number of Securities	31					31
Available-for-sale Securities, Privately Issued Residential Mortgage-backed Securities, Credit losses Recognized [Abstract]
Available-for-sale Securities, Privately Issued Residential Mortgage-backed Securities, Number of Securities with Credit Losses In Current Period	0					29
Amount of Credit Losses Recognized in Current Period	0					18,220,000
Perpetual Preferred, Equity Securities and Mutual Funds [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Amortized Cost Basis	41,240,000					41,240,000
Available-for-sale Securities, Fair Value	44,191,000					44,191,000
Available-for-sale Securities, Debt Maturities, Nominal Yield [Abstract]
Available-for-sale Securities, Debt Maturities, Nominal Yield	1.33%					1.33%
Perpetual preferred stock [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Amortized Cost Basis	22,171,000		22,171,000			22,171,000
Available-for-sale Securities, Fair Value	22,863,000		25,072,000			22,863,000
Available-for-sale Securities, Gross Unrealized Gains	705,000	[1]	2,901,000	[2]		705,000	[1]
Available-for-sale Securities, Gross Unrealized Loss	(13,000)	[1]	0	[2]		(13,000)	[1]
Available-for-Sale Securities, Other Than Temporary Impairments	0	[3]	0	[3]		0	[3]
Available-for-sale Securities, Continuous Unrealized Loss Position, Qualitative Disclosure [Abstract]
Available-for-sale, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Positions	1		0			1
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	4,988,000		0			4,988,000
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	4,988,000		0			4,988,000
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	13,000		0			13,000
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	13,000		0			13,000
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	[4]				0	[4]
Available-for-sale Securities, Portfolio Concentration US Govt or GSE Securities Not Rated, Fair Value	0	[4]				0	[4]
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	11,406,000					11,406,000
Available-for-sale Securities, Portfolio Concentration Rated A To BBB, Fair Value	11,859,000					11,859,000
Available-for-sale Securities, Portfolio Concentration Rated Below Investment Grade, Amortized Cost	10,765,000					10,765,000
Available-for-sale Securities, Portfolio Concentration Rated Below Investment Grade, Fair Value	11,004,000					11,004,000
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 Basis	19,069,000		24,593,000			19,069,000
Available-for-sale Securities, Fair Value	21,328,000		27,557,000			21,328,000
Available-for-sale Securities, Gross Unrealized Gains	2,326,000	[1]	3,242,000	[2]		2,326,000	[1]
Available-for-sale Securities, Gross Unrealized Loss	(67,000)	[1]	(278,000)	[2]		(67,000)	[1]
Available-for-Sale Securities, Other Than Temporary Impairments	0	[3]	0	[3]		0	[3]
Available-for-sale Securities, Continuous Unrealized Loss Position, Qualitative Disclosure [Abstract]
Available-for-sale, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Positions	118		22			118
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	2,070,000		202,000			2,070,000
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value	0		2,161,000			0
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	2,070,000		2,363,000			2,070,000
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	67,000		1,000			67,000
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	0		277,000			0
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss	67,000		278,000			67,000
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	[4]				0	[4]
Available-for-sale Securities, Portfolio Concentration US Govt or GSE Securities Not Rated, Fair Value	0	[4]				0	[4]
Available-for-sale securities, Portfolio Concentration Rated AAA To AA, Amortized Cost	4,000					4,000
Available-for-sale Securities, Portfolio Concentration Rated AAA To AA, Fair Value	457,000					457,000
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	19,065,000					19,065,000
Available-for-sale Securities, Portfolio Concentration Not Rated, Fair Value	20,871,000					20,871,000
Available-for-sale Securities, Privately Issued Residential Mortgage-backed Securities, Credit losses Recognized [Abstract]
Amount of Credit Losses Recognized in Current Period	$ 0		$ (457,000)		$ 0

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

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

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

[4] 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.

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

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

[7] 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.

[8] 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.

[9] Includes the following securities for which an unrealized loss remains in AOCI after an other-than-temporary credit loss has been recognized in income:Alt-A loans 7 11,043 756 30,774 977 41,817 1,733Jumbo-A loans 9 14,642 709 — — 14,642 709

[10] Includes the following securities for which an unrealized loss remains in AOCI after an other-than-temporary credit loss has been recognized in income:Alt-A loans 12 $— $— $87,907 $2,580 $87,907 $2,580Jumbo-A loans 10 — — 29,128 1,602 29,128 1,602

[11] Federal Housing Finance Agency