Consolidated Statement of Stockholders Equity and Comprehensive Income (Loss) (Parenthetical) (USD $)	12 Months Ended
Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Preferred stock dividends, per share	$ 4.00	$ 4.00	$ 4.00

Aggregate dividends declared during the period for each share of preferred stock outstanding.

No definition available.

Name:	us-gaap_PreferredStockDividendsPerShareDeclared
Namespace Prefix:	us-gaap_
Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	duration