Accounting Policies (Details) (USD $) In Millions, unless otherwise specified	6 Months Ended
Jun. 30, 2011
Charge off threshold - small business commercial loans	$ 1
Loan-to-value ratio	90.00%
Other Assets - BlackRock Series C Preferred Stock [Member]
Total shares accounted for relating to BlackRock Series C Preferred Stock	2.9

Balance held at close of period in number of shares.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Section 12C
-Paragraph Column B
-Article 12

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Section 12
-Paragraph Column B
-Article 12

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Section 14
-Paragraph Column B
-Article 12

Name:	us-gaap_InvestmentOwnedBalanceShares
Namespace Prefix:	us-gaap
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant