Covered Loans (Narrative) (Details) (USD $)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011
Covered Loans [Line Items]
Covered loans	$ 372,333,000	$ 626,360,000
Outstanding covered loans including principal interest fees and penalties	534,300,000	726,800,000
Loss sharing asset, FDIC indemnification asset	107,400,000
Loss sharing asset, loss share receivable	8,300,000
Percentage of increase in indemnification asset measured as a result of impairment	80.00%
Percentage of prospective yield adjustments offset	80.00%
Noninterest loan expenses reimbursable by FDIC included in other assets	886,000	1,200,000
Noninterest loan expense related payable to FDIC	521,000	20,900,000
Expected Indemnification Payments [Member]
Covered Loans [Line Items]
Loss sharing asset, FDIC indemnification asset	99,500,000
To Be Amortized Against Future Accreted Interest Income [Member]
Covered Loans [Line Items]
Loss sharing asset, FDIC indemnification asset	$ 7,900,000