Significant Accounting Policies (Details) (Accounting Standards Update 2010-11 [Member], Mortgage backed and asset backed securities, USD $) In Thousands, unless otherwise specified	12 Months Ended
Dec. 31, 2010
Accounting Standards Update 2010-11 [Member] \| Mortgage backed and asset backed securities
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cumulative adjustment effect of ASU 2010-11	$ 41,889

The gross gains that make up a cumulative-effect adjustment on retained earnings related to the election of the fair value option.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 815

-SubTopic 10

-Section 65

-Paragraph 5

-Subparagraph (f)

-URI http://asc.fasb.org/extlink&oid=7480679&loc=SL6849109-159117

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration