Securities (Tables)

9 Months Ended

Sep. 30, 2013

Marketable Securities [Abstract]

Trading Securities [Table Text Block]

The fair value and net unrealized gain (loss) included in trading securities is as follows (in thousands):

	September 30, 2013					December 31, 2012					September 30, 2012
	Fair Value		Net Unrealized Gain (Loss)			Fair Value		Net Unrealized Gain (Loss)			Fair Value		Net Unrealized Gain (Loss)
U.S. Government agency debentures	$	74,632	$	(598	)	$	16,545	$	(57	)	$	3,100	$	1
U.S. agency residential mortgage-backed securities	26,129		456			86,361		447			119,835		566
Municipal and other tax-exempt securities	37,057		81			90,326		(226		)	58,150		118
Other trading securities	13,069		(25		)	20,870		(13		)	23,157		(1		)
Total	$	150,887	$	(86	)	$	214,102	$	151		$	204,242	$	684

Investment Securities (Held-to-Maturity) [Table Text Block]

The amortized cost and fair values of investment securities are as follows (in thousands):

	September 30, 2013
	Amortized		Carrying		Fair		Gross Unrealized2
	Cost		Value1		Value		Gain		Loss
Municipal and other tax-exempt	$	409,542	$	409,542	$	407,562	$	2,316	$	(4,296	)
U.S. agency residential mortgage-backed securities – Other	53,858		56,182		58,442		2,260		—
Other debt securities	178,501		178,501		188,475		10,094		(120		)
Total	$	641,901	$	644,225	$	654,479	$	14,670	$	(4,416	)

¹  Carrying value includes $2.3 million of net unrealized gain which remains in Accumulated other comprehensive income (“AOCI”) in the Consolidated Balance Sheets related to certain securities transferred from the Available for Sale securities portfolio to the Investment securities portfolio as discussed in greater detail following.

²  Gross unrealized gains and losses are not recognized in AOCI in the Consolidated Balance Sheets.

	December 31, 2012
	Amortized		Carrying		Fair		Gross Unrealized2
	Cost		Value1		Value		Gain		Loss
Municipal and other tax-exempt	$	232,700	$	232,700	$	235,940	$	3,723	$	(483	)
U.S. agency residential mortgage-backed securities – Other	77,726		82,767		85,943		3,176		—
Other debt securities	184,067		184,067		206,575		22,528		(20		)
Total	$	494,493	$	499,534	$	528,458	$	29,427	$	(503	)

¹  Carrying value includes $5.0 million of net unrealized gain which remains in Accumulated other comprehensive income (“AOCI”) in the Consolidated Balance Sheets related to certain securities transferred from the Available for Sale securities portfolio to the Investment securities portfolio as discussed in greater detail following.

²  Gross unrealized gains and losses are not recognized in AOCI in the Consolidated Balance Sheets.

	September 30, 2012
	Amortized		Carrying		Fair		Gross Unrealized2
	Cost		Value1		Value		Gain		Loss
Municipal and other tax-exempt	$	155,144	$	155,144	$	159,464	$	4,329	$	(9	)
U.S. agency residential mortgage-backed securities – Other	85,699		91,911		95,128		3,356		(139		)
Other debt securities	185,059		185,059		205,766		20,737		(30		)
Total	$	425,902	$	432,114	$	460,358	$	28,422	$	(178	)

¹  Carrying value includes $6.2 million of net unrealized gain which remains in Accumulated other comprehensive income (“AOCI”) in the Consolidated Balance Sheets related to certain securities transferred from the Available for Sale securities portfolio to the Investment securities portfolio as discussed in greater detail following.

²  Gross unrealized gains and losses are not recognized in AOCI in the Consolidated Balance Sheets.

During the three months ended September 30, 2011, the Company transferred certain U.S. government agency residential mortgage-backed securities from the available for sale portfolio to the investment securities (held-to-maturity) portfolio as the Company has the positive intent and ability to hold these securities to maturity. No gains or losses were recognized in the Consolidated Statement of Earnings at the time of the transfer. Transfers of debt securities into the investment securities portfolio (held-to-maturity) are made at fair value at the date of transfer. The unrealized holding gain or loss at the date of transfer is retained in accumulated other comprehensive income and in the carrying value of the investment securities portfolio.  Such amounts are amortized over the estimated remaining life of the security as an adjustment to yield, offsetting the related amortization of the premium or accretion of the discount on the transferred securities. At the time of transfer, the fair value totaled $131 million, amortized cost totaled $118 million and the pretax unrealized gain totaled $13 million.

The amortized cost and fair values of investment securities at September 30, 2013, by contractual maturity, are as shown in the following table (dollars in thousands):

	Less than One Year			One to Five Years			Six to Ten Years			Over Ten Years			Total			Weighted Average Maturity²
Municipal and other tax-exempt:
Carrying value	$	28,674		$	277,808		$	93,703		$	9,357		$	409,542		3.92
Fair value	28,928			276,908			92,195			9,531			407,562
Nominal yield¹	3.35		%	1.52		%	2.29		%	2.74		%	1.85		%
Other debt securities:
Carrying value	9,631			32,542			35,539			100,789			178,501			8.78
Fair value	9,647			32,883			36,445			109,500			188,475
Nominal yield	3.98		%	5.08		%	5.51		%	6.27		%	5.78		%
Total fixed maturity securities:
Carrying value	$	38,305		$	310,350		$	129,242		$	110,146		$	588,043		5.39
Fair value	38,575			309,791			128,640			119,031			596,037
Nominal yield	3.51		%	1.90		%	3.17		%	5.97		%	3.04		%
Residential mortgage-backed securities:
Carrying value													$	56,182		³
Fair value													58,442
Nominal yield4													2.73		%
Total investment securities:
Carrying value													$	644,225
Fair value													654,479
Nominal yield													3.02		%

¹  Calculated on a taxable equivalent basis using a 39% effective tax rate.

²  Expected maturities may differ from contractual maturities, because borrowers may have the right to call or prepay obligations with or without penalty.

³  The average expected lives of residential mortgage-backed securities were 4.2 years based upon current prepayment assumptions.

⁴  The nominal yield on residential 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 for current yields on the investment securities portfolio.

Available For Sale Securities [Table Text Block]

The amortized cost and fair value of available for sale securities are as follows (in thousands):

	September 30, 2013
	Amortized		Fair		Gross Unrealized1
	Cost		Value		Gain		Loss			OTTI²
U.S. Treasury	$	1,052	$	1,052	$	—	$	—		$	—
Municipal and other tax-exempt	93,897		95,440		2,792		(1,249		)	—
Residential mortgage-backed securities:
U. S. government agencies:
FNMA	4,513,161		4,544,505		81,984		(50,640		)	—
FHLMC	2,412,948		2,412,116		30,673		(31,505		)	—
GNMA	978,361		984,065		11,054		(5,350		)	—
Other	38,979		40,701		1,722		—			—
Total U.S. government agencies	7,943,449		7,981,387		125,433		(87,495		)	—
Private issue:
Alt-A loans	109,234		109,592		2,970		—			(2,612		)
Jumbo-A loans	118,312		121,308		3,816		(138		)	(682		)
Total private issue	227,546		230,900		6,786		(138		)	(3,294		)
Total residential mortgage-backed securities	8,170,995		8,212,287		132,219		(87,633		)	(3,294		)
Commercial mortgage-backed securities guaranteed by U.S. government agencies	1,985,924		1,946,295		354		(39,983		)	—
Other debt securities	35,091		35,362		459		(188		)	—
Perpetual preferred stock	22,171		23,680		1,534		(25		)	—
Equity securities and mutual funds	56,348		58,787		2,479		(40		)	—
Total	$	10,365,478	$	10,372,903	$	139,837	$	(129,118	)	$	(3,294	)

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.

	December 31, 2012
	Amortized		Fair		Gross Unrealized¹
	Cost		Value		Gain		Loss			OTTI²
U.S. Treasury	$	1,000	$	1,002	$	2	$	—		$	—
Municipal and other tax-exempt	84,892		87,142		2,414		(164		)	—
Residential mortgage-backed securities:
U. S. government agencies:
FNMA	5,308,463		5,453,549		146,247		(1,161		)	—
FHLMC	2,978,608		3,045,564		66,956		—			—
GNMA	1,215,554		1,237,041		21,487		—			—
Other	148,025		153,667		5,642		—			—
Total U.S. government agencies	9,650,650		9,889,821		240,332		(1,161		)	—
Private issue:
Alt-A loans	124,314		123,174		1,440		—			(2,580		)
Jumbo-A loans	198,588		201,989		5,138		(134		)	(1,603		)
Total private issue	322,902		325,163		6,578		(134		)	(4,183		)
Total residential mortgage-backed securities	9,973,552		10,214,984		246,910		(1,295		)	(4,183		)
Commercial mortgage-backed securities guaranteed by U.S. government agencies	890,746		895,075		5,006		(677		)	—
Other debt securities	35,680		36,389		709		—			—
Perpetual preferred stock	22,171		25,072		2,901		—			—
Equity securities and mutual funds	24,593		27,557		3,242		(278		)	—
Total	$	11,032,634	$	11,287,221	$	261,184	$	(2,414	)	$	(4,183	)

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.

	September 30, 2012
	Amortized		Fair		Gross Unrealized1
	Cost		Value		Gain		Loss			OTTI²
U.S. Treasury	$	1,000	$	1,002	$	2	$	—		$	—
Municipal and other tax-exempt	86,326		87,969		2,760		(152		)	(965		)
Residential mortgage-backed securities:
U. S. government agencies:
FNMA	5,740,232		5,900,174		161,314		(1,372		)	—
FHLMC	3,322,692		3,400,215		77,523		—			—
GNMA	1,151,058		1,181,134		30,076		—			—
Other	167,262		173,298		6,036		—			—
Total U.S. government agencies	10,381,244		10,654,821		274,949		(1,372		)	—
Private issue:
Alt-A loans	128,090		123,583		663		—			(5,170		)
Jumbo-A loans	208,900		208,139		3,617		(152		)	(4,226		)
Total private issue	336,990		331,722		4,280		(152		)	(9,396		)
Total residential mortgage-backed securities	10,718,234		10,986,543		279,229		(1,524		)	(9,396		)
Commercial mortgage-backed securities guaranteed by U.S. government agencies	336,130		339,095		3,271		(306		)	—
Other debt securities	35,710		36,456		746		—			—
Perpetual preferred stock	22,170		25,288		3,118		—			—
Equity securities and mutual funds	25,409		30,081		4,998		(326		)	—
Total	$	11,224,979	$	11,506,434	$	294,124	$	(2,308	)	$	(10,361	)

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.

The amortized cost and fair values of available for sale securities at September 30, 2013, by contractual maturity, are as shown in the following table (dollars in thousands):

	Less than One Year			One to Five Years			Six to Ten Years			Over Ten Years				Total			Weighted Average Maturity5
U.S. Treasuries:
Amortized cost	$	1,052		$	—		$	—		$	—			$	1,052		1.42
Fair value	1,052			—			—			—				1,052
Nominal yield	0.24		%	—		%	—		%	—		%		0.24		%
Municipal and other tax-exempt:
Amortized cost	$	1,379		$	34,349		$	5,446		$	52,723			$	93,897		14.50
Fair value	1,404			35,542			5,689			52,805				95,440
Nominal yield¹	—		%	0.97		%	0.51		%	2.62		%	6	1.85		%
Commercial mortgage-backed securities:
Amortized cost	$	—		$	520,499		$	1,150,637		$	314,788			$	1,985,924		10.18
Fair value	—			514,668			1,121,936			309,691				1,946,295
Nominal yield	—		%	1.11		%	1.37		%	1.36		%		1.30		%
Other debt securities:
Amortized cost	$	—		$	30,191		$	—		$	4,900			$	35,091		5.56
Fair value	—			30,650			—			4,712				35,362
Nominal yield	—		%	1.80		%	—		%	1.54		%	6	1.77		%
Total fixed maturity securities:
Amortized cost	$	2,431		$	585,039		$	1,156,083		$	372,411			$	2,115,964		10.29
Fair value	2,456			580,860			1,127,625			367,208				2,078,149
Nominal yield	—		%	1.13		%	1.36		%	1.54		%		1.33		%
Residential mortgage-backed securities:
Amortized cost														$	8,170,995		2
Fair value														8,212,287
Nominal yield4														1.92		%
Equity securities and mutual funds:
Amortized cost														$	78,519		³
Fair value														82,467
Nominal yield														0.70		%
Total available-for-sale securities:
Amortized cost														$	10,365,478
Fair value														10,372,903
Nominal yield														1.79		%

¹  Calculated on a taxable equivalent basis using a 39% effective tax rate.

²  The average expected lives of mortgage-backed securities were 3.5 based upon current prepayment assumptions.

³  Primarily common stock and preferred stock of corporate issuers with no stated maturity.

⁴  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.

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

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.

Sales of available for sale securities resulted in gains and losses as follows (in thousands):

	Three Months Ended					Nine Months Ended
	September 30,					September 30,
	2013			2012		2013			2012
Proceeds	$	355,650		$	209,325	$	2,140,531		$	1,660,876
Gross realized gains	3,164			7,967		18,948			40,133
Gross realized losses	(2,686		)	—		(9,862		)	(7,354		)
Related federal and state income tax expense	184			3,099		3,533			12,751

Securities Pledged As Collateral [Table Text Block]

	September 30, 2013		December 31, 2012		September 30, 2012
Investment:
Carrying value	$	92,442	$	117,346	$	153,224
Fair value	95,658		121,647		158,899
Available for sale:
Amortized cost	5,020,732		4,070,250		3,634,955
Fair value	5,009,611		4,186,390		3,763,664

Schedule of Unrealized Loss on Investments [Table Text Block]

or September 30, 2012.

Temporarily Impaired Securities as of September 30, 2013

(in thousands):

	Number of Securities	Less Than 12 Months				12 Months or Longer				Total
		Fair Value		Unrealized Loss		Fair Value		Unrealized Loss		Fair Value		Unrealized Loss
Investment:
Municipal and other tax-exempt	136	$	257,359	$	4,292	$	803	$	4	$	258,162	$	4,296
U.S. Agency residential mortgage-backed securities – Other	—	—		—		—		—		—		—
Other debt securities	29	1,326		59		780		61		2,106		120
Total investment	165	$	258,685	$	4,351	$	1,583	$	65	$	260,268	$	4,416

	Number of Securities	Less Than 12 Months				12 Months or Longer				Total
		Fair Value		Unrealized Loss		Fair Value		Unrealized Loss		Fair Value		Unrealized Loss
Available for sale:
U.S. Treasury	—	$	—	$	—	$	—	$	—	$	—	$	—
Municipal and other tax-exempt1	46	$	20,274	$	352	$	19,575	$	897	$	39,849	$	1,249
Residential mortgage-backed securities:
U. S. agencies:
FNMA	79	2,328,213		50,640		—		—		2,328,213		50,640
FHLMC	46	1,402,010		31,505		—		—		1,402,010		31,505
GNMA	23	674,512		5,350		—		—		674,512		5,350
Total U.S. agencies	148	4,404,735		87,495		—		—		4,404,735		87,495
Private issue1:
Alt-A loans	10	11,336		707		48,849		1,905		60,185		2,612
Jumbo-A loans	10	15,326		682		11,742		138		27,068		820
Total private issue	20	26,662		1,389		60,591		2,043		87,253		3,432
Total residential mortgage-backed securities	168	4,431,397		88,884		60,591		2,043		4,491,988		90,927
Commercial mortgage-backed securities guaranteed by U.S. government agencies	116	1,803,008		39,983		—		—		1,803,008		39,983
Other debt securities	3	4,712		188		—		—		4,712		188
Perpetual preferred stocks	1	4,975		25		—		—		4,975		25
Equity securities and mutual   funds	97	1,529		40		—		—		1,529		40
Total available for sale	431	$	6,265,895	$	129,472	$	80,166	$	2,940	$	6,346,061	$	132,412

¹Includes the following securities for which an unrealized loss remains in AOCI after an other-than-temporary credit loss has been recognized in income:

Municipal and other tax-exempt	—	$	—	$	—	$	—	$	—	$	—	$	—
Alt-A loans	10	11,336		707		48,849		1,905		60,185		2,612
Jumbo-A loans	9	15,326		682		—		—		15,326		682

Temporarily Impaired Securities as of December 31, 2012

(In thousands)

	Number of Securities	Less Than 12 Months				12 Months or Longer				Total
		Fair Value		Unrealized Loss		Fair Value		Unrealized Loss		Fair Value		Unrealized Loss
Investment:
Municipal and other tax-exempt	53	$	92,768	$	483	$	—	$	—	$	92,768	$	483
U.S. Agency residential mortgage-backed securities – Other	—	—		—		—		—		—		—
Other debt securities	14	881		20		—		—		881		20
Total investment	67	$	93,649	$	503	$	—	$	—	$	93,649	$	503

	Number of Securities	Less Than 12 Months				12 Months or Longer				Total
		Fair Value		Unrealized Loss		Fair Value		Unrealized Loss		Fair Value		Unrealized Loss
Available for sale:
Municipal and other tax-exempt	38	$	6,150	$	11	$	26,108	$	153	$	32,258	$	164
Residential mortgage-backed securities:
U. S. agencies:
FNMA	12	161,828		1,161		—		—		161,828		1,161
FHLMC	—	—		—		—		—		—		—
GNMA	—	—		—		—		—		—		—
Total U.S. agencies	12	161,828		1,161		—		—		161,828		1,161
Private issue1:
Alt-A loans	12	—		—		87,907		2,580		87,907		2,580
Jumbo-A loans	11	—		—		43,252		1,737		43,252		1,737
Total private issue	23	—		—		131,159		4,317		131,159		4,317
Total residential mortgage-backed securities	35	161,828		1,161		131,159		4,317		292,987		5,478
Commercial mortgage-backed securities guaranteed by U.S. government agencies	8	275,065		677		—		—		275,065		677
Other debt securities	3	4,899		—		—		—		4,899		—
Perpetual preferred stocks	—	—		—		—		—		—		—
Equity securities and mutual funds	22	202		1		2,161		277		2,363		278
Total available for sale	106	$	448,144	$	1,850	$	159,428	$	4,747	$	607,572	$	6,597

¹  Includes the following securities for which an unrealized loss remains in AOCI after an other-than-temporary credit loss has been recognized in income:

Municipal and other tax-exempt	—	$	—	$	—	$	—	$	—	$	—	$	—
Alt-A loans	12	$	—	$	—	$	87,907	$	2,580	$	87,907	$	2,580
Jumbo-A loans	10	—		—		29,128		1,602		29,128		1,602

Temporarily Impaired Securities as of September 30, 2012

(In thousands)

	Number of Securities	Less Than 12 Months				12 Months or Longer				Total
		Fair Value		Unrealized Loss		Fair Value		Unrealized Loss		Fair Value		Unrealized Loss
Investment:
Municipal and other tax-exempt	6	$	7,548	$	9	$	—	$	—	$	7,548	$	9
U.S. Agency residential mortgage-backed securities – Other	1	—		—		19,066		139		19,066		139
Other debt securities	14	871		30		—		—		871		30
Total investment	21	$	8,419	$	39	$	19,066	$	139	$	27,485	$	178

	Number of Securities	Less Than 12 Months				12 Months or Longer				Total
		Fair Value		Unrealized Loss		Fair Value		Unrealized Loss		Fair Value		Unrealized Loss
Available for sale:
Municipal and other tax-exempt1	51	$	13,492	$	970	$	27,485	$	147	$	40,977	$	1,117
Residential mortgage-backed securities:
U. S. agencies:
FNMA	12	483,258		1,372		—		—		483,258		1,372
FHLMC	—	—		—		—		—		—		—
GNMA	—	—		—		—		—		—		—
Total U.S. agencies	12	483,258		1,372		—		—		483,258		1,372
Private issue1:
Alt-A loans	13	—		—		105,862		5,170		105,862		5,170
Jumbo-A loans	15	—		—		121,746		4,378		121,746		4,378
Total private issue	28	—		—		227,608		9,548		227,608		9,548
Total residential mortgage-backed securities	40	483,258		1,372		227,608		9,548		710,866		10,920
Commercial mortgage-backed securities guaranteed by U.S. government agencies	8	42,445		306		—		—		42,445		306
Other debt securities	—	—		—		—		—		—		—
Perpetual preferred stocks	—	—		—		—		—		—		—
Equity securities and mutual funds	2	2,551		326		—		—		2,551		326
Total available for sale	101	$	541,746	$	2,974	$	255,093	$	9,695	$	796,839	$	12,669

¹  Includes the following securities for which an unrealized loss remains in AOCI after an other-than-temporary credit loss has been recognized in income:

Municipal and other tax-exempt	21	$	12,431	$	965	$	—	$	—	$	12,431	$	965
Alt-A loans	13	—		—		105,862		5,170		105,862		5,170
Jumbo-A loans	14	—		—		107,071		4,226		107,071		4,226

On a quarterly basis, the

Investments by Lowest Credit Rating [Table Text Block]

At September 30, 2013, the composition of the Company’s investment and available for sale securities portfolios by the lowest current credit rating assigned by any of the three nationally-recognized rating agencies is as follows (in thousands):

	U.S. Govt / GSE1				AAA - AA				A - BBB				Below Investment Grade				Not Rated				Total
	Carrying Value		Fair Value		Carrying Value		Fair Value		Carrying Value		Fair Value		Carrying Value		Fair Value		Carrying Value		Fair Value		Carrying Value		Fair Value
Investment:
Municipal and other tax-exempt	$	—	$	—	$	275,067	$	271,781	$	21,162	$	21,405	$	—	$	—	$	113,313	$	114,376	$	409,542	$	407,562
Mortgage-backed securities -- other	56,182		58,442		—		—		—		—		—		—		—		—		56,182		58,442
Other debt securities	—		—		167,463		177,502		—		—		—		—		11,038		10,973		178,501		188,475
Total investment securities	$	56,182	$	58,442	$	442,530	$	449,283	$	21,162	$	21,405	$	—	$	—	$	124,351	$	125,349	$	644,225	$	654,479

	U.S. Govt / GSE1				AAA - AA				A - BBB				Below Investment Grade				Not Rated				Total
	Amortized Cost		Fair Value		Amortized Cost		Fair Value		Amortized Cost		Fair Value		Amortized Cost		Fair Value		Amortized Cost		Fair Value		Amortized Cost		Fair Value
Available for Sale:
U.S. Treasury	$	1,052	$	1,052	$	—	$	—	$	—	$	—	$	—	$	—	$	—	$	—	$	1,052	$	1,052
Municipal and other tax-exempt	—		—		47,747		48,564		15,819		15,525		17,924		19,140		12,407		12,211		93,897		95,440
Residential mortgage-backed securities:
U. S. government agencies:
FNMA	4,513,161		4,544,505		—		—		—		—		—		—		—		—		4,513,161		4,544,505
FHLMC	2,412,948		2,412,116		—		—		—		—		—		—		—		—		2,412,948		2,412,116
GNMA	978,361		984,065		—		—		—		—		—		—		—		—		978,361		984,065
Other	38,979		40,701		—		—		—		—		—		—		—		—		38,979		40,701
Total U.S. government agencies	7,943,449		7,981,387		—		—		—		—		—		—		—		—		7,943,449		7,981,387
Private issue:
Alt-A loans	—		—		—		—		—		—		109,234		109,592		—		—		109,234		109,592
Jumbo-A loans	—		—		—		—		—		—		118,312		121,308		—		—		118,312		121,308
Total private issue	—		—		—		—		—		—		227,546		230,900		—		—		227,546		230,900
Total residential mortgage-backed securities	7,943,449		7,981,387		—		—		—		—		227,546		230,900		—		—		8,170,995		8,212,287
Commercial mortgage-backed securities guaranteed by U.S. government agencies	1,985,924		1,946,295		—		—		—		—		—		—		—		—		1,985,924		1,946,295
Other debt securities	—		—		4,900		4,712		30,191		30,650		—		—		—		—		35,091		35,362
Perpetual preferred stock	—		—		—		—		11,406		11,822		10,765		11,858		—		—		22,171		23,680
Equity securities and mutual funds	—		—		4		441		—		—		—		—		56,344		58,346		56,348		58,787
Total available for sale securities	$	9,930,425	$	9,928,734	$	52,651	$	53,717	$	57,416	$	57,997	$	256,235	$	261,898	$	68,751	$	70,557	$	10,365,478	$	10,372,903

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.

Schedule of Privately Issued Residential Mortgage-backed Securities [Table Text Block]

						Credit Losses Recognized
						Three months ended
						September 30, 2013			Life-to-date
	Number of Securities	Amortized Cost		Fair Value		Number of Securities	Amount		Number of Securities	Amount
Alt-A	16	$	109,234	$	109,592	1	$	139	16	$	49,126
Jumbo-A	29	118,312		121,308		—	—		29	18,220
Total	45	$	227,546	$	230,900	1	$	139	45	$	67,346

Other-than-temporary impairement, Private Lable Mortgage-Backed Securities, Assumptions Used to Develop Projected Cash Flows [Table Text Block]

The primary assumptions used in this evaluation were:

	September 30, 2013	December 31, 2012	September 30, 2012
Unemployment rate	Increasing to 7.5% over the next 12 months and remain at 7.5% thereafter	Increasing to 8.5% over the next 12 months, dropping to 8% over the following 21 months and holding at 8% 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 5% over the next 12 months, then flat for the following 12 months and then appreciating at 2% per year thereafter.	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.	Starting with current depreciated housing prices based on information derived from the FHFA1, depreciating 2% over the next 12 months and then appreciating at 2% per year thereafter.
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.	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.	Estimated cash flows were discounted at rates that range from 2.00% to 6.25% based on our current expected yields.

Rollforward Other-than-temporary Impairment Credit Losses Recognized in Earnings [Table Text Block]

	Three Months Ended					Nine Months Ended
	September 30,					September 30,
	2013			2012		2013			2012
Balance of credit-related OTTI recognized on available for sale debt, beginning of period	$	76,027		$	72,915	$	75,228		$	76,131
Additions for credit-related OTTI not previously recognized	67			—		619			248
Additions for increases in credit-related OTTI previously recognized when there is no intent to sell and no requirement to sell before recovery of amortized cost	73			1,104		320			5,436
Reductions for change in intent to hold before recovery	(3,589		)	—		(3,589		)	—
Sales	(5,232		)	—		(5,232		)	(7,796		)
Balance of credit-related OTTI recognized on available for sale debt securities, end of period	$	67,346		$	74,019	$	67,346		$	74,019

Fair Value Option Securities [Table Text Block]

The fair value and net unrealized gain (loss) included in Fair value option securities is as follows (in thousands):

	September 30, 2013					December 31, 2012				September 30, 2012
	Fair Value		Net Unrealized Gain (Loss)			Fair Value		Net Unrealized Gain		Fair Value		Net Unrealized Gain
U.S. agency residential mortgage-backed securities	$	163,567	$	(5,365	)	$	257,040	$	3,314	$	305,445	$	13,827
Corporate debt securities	—		—			26,486		1,409		26,442		1,359
Other securities	4,293		1			770		47		—		—
Total	$	167,860	$	(5,364	)	$	284,296	$	4,770	$	331,887	$	15,186