Consolidated Statements of Changes in Shareholders' Equity (Parenthetical)	3 Months Ended
Mar. 31, 2012	Mar. 31, 2011
Consolidated Statements of Changes in Shareholders' Equity
Preferred Stock, Dividend Rate, Percentage	5.00%	5.00%

The percentage rate used to calculate dividend payments on preferred stock.

No definition available.

Name:	us-gaap_PreferredStockDividendRatePercentage
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration