Other-Than-Temporary Impairment (Impact of OTTI Credit and Noncredit Losses Recorded on Investment Securities) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended	9 Months Ended
Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011
Other than Temporary Impairment, Disclosure [Line Items]
OTTI Related to Credit Loss	$ (186)	$ (6,173)	$ (11,024)	$ (37,529)
OTTI Related to Noncredit Loss	186	6,069	8,833	34,306
Total OTTI losses (Note 6)	0	(104)	(2,191)	(3,223)
Private label MBS [Member]
Other than Temporary Impairment, Disclosure [Line Items]
OTTI Related to Credit Loss	(186)	(6,173)	(11,024)	(37,529)
OTTI Related to Noncredit Loss	186	6,069	8,833	34,306
Total OTTI losses (Note 6)	0	(104)	(2,191)	(3,223)
HELOCs [Member]
Other than Temporary Impairment, Disclosure [Line Items]
OTTI Related to Credit Loss	0	(150)	(1,084)	(787)
OTTI Related to Noncredit Loss	0	150	1,084	787
Total OTTI losses (Note 6)	0		0	0
Prime [Member] \| Private label residential MBS [Member]
Other than Temporary Impairment, Disclosure [Line Items]
OTTI Related to Credit Loss	(82)	(1,805)	(8,566)	(12,000)
OTTI Related to Noncredit Loss	82	1,701	6,375	8,777
Total OTTI losses (Note 6)	0	(104)	(2,191)	(3,223)
Alt-A [Member] \| Private label residential MBS [Member]
Other than Temporary Impairment, Disclosure [Line Items]
OTTI Related to Credit Loss	(104)	(4,218)	(1,051)	(24,608)
OTTI Related to Noncredit Loss	104	4,218	1,051	24,608
Total OTTI losses (Note 6)	0		0	0
Subprime [Member] \| Private label residential MBS [Member]
Other than Temporary Impairment, Disclosure [Line Items]
OTTI Related to Credit Loss	0	0	(323)	(134)
OTTI Related to Noncredit Loss	0	0	323	134
Total OTTI losses (Note 6)	$ 0		$ 0	$ 0

The amount by which the fair value of an investment is less than the amortized cost basis or carrying amount of that investment at the balance sheet date and the decline in fair value is deemed to be other than temporary, before considering whether or not such amount is recognized in earnings or other comprehensive income.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name FASB Staff Position (FSP)

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Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

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Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 115

-Paragraph 16

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Reference 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name FASB Staff Position (FSP)

-Number FAS115-1/124-1

-Paragraph 16B

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 5: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name FASB Staff Position (FSP)

-Number FAS115-1/124-1

-Paragraph 15D

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Reference 6: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

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Reference 7: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name FASB Staff Position (FSP)

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+ Details

- Definition

Before tax amount of other than temporary impairment (OTTI) on a debt security, categorized as either available-for-sale or held-to-maturity, recognized in other comprehensive income (loss), attributable to the parent entity.

+ References+ Details

- Definition

The amount of other than temporary impairment (OTTI) losses on equity securities, OTTI related to credit losses on debt securities, and OTTI losses on debt securities when the entity intends to sell the securities or it is more likely than not that the entity will be required to sell the securities before recovery of its amortized cost basis. Additionally, this item includes OTTI losses recognized during the period on investments accounted for under the cost method of accounting.

+ References+ Details