Advances From The Federal Home Loan Bank ("FHLB") (Details) (USD $)	1 Months Ended	3 Months Ended		6 Months Ended		12 Months Ended
	Jan. 31, 2011	Jun. 30, 2011	Mar. 31, 2011	Jun. 30, 2011	Jun. 30, 2010	Dec. 31, 2010
Advances From The Federal Home Loan Bank ("FHLB")
Federal home loan bank advances		$ 250,000,000		$ 250,000,000		$ 550,000,000
Increase (decrease) in loans from federal home loan banks				300,000,000
Federal home loan bank prepaid advances		100,000,000	200,000,000		65,000,000
Federal home loan bank weighted average interest rate		4.33%	4.29%	4.33%	3.49%
Federal home loan bank prepayment penalties	909,000	3,500,000		12,300,000
Federal home loan bank prepaid advances under put option		$ 250,000,000		$ 250,000,000		$ 550,000,000
Federal home loan bank weighted average interest rate under put option				4.58%		4.43%