Loans Receivable (Narrative) (Details) (USD $)	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Loans Receivable [Line Items]
Percentage of covered loan loss, covered under loss share agreements	80.00%
Percentage of covered loan loss that exceeds the threshold, covered under loss share agreements	95.00%
Interest income, nonaccrual loans	$ 4,113,000	$ 2,198,000	$ 1,388,000
Provision for loan losses	5,893,000
Indemnification asset for portion of losses recoverable	57,121,000	64,922,000	147,000
Total TDRs	23,953,000	17,472,000
Total non-covered TDRs included in TDRs		16,726,000
Total covered TDRs included in TDRs	10,567,000
Covered Loans [Member]
Loans Receivable [Line Items]
Indemnification asset for portion of losses recoverable	$ 57,121,000	$ 64,922,000	$ 147,000