Other Real Estate Owned and Property Acquired in Settlement of Loans (Real Estate Owned) (Details) (USD $)	3 Months Ended		6 Months Ended
	Jun. 30, 2012 assets	Jun. 30, 2011	Jun. 30, 2012 assets	Jun. 30, 2011
Real Estate Acquired Through Foreclosure [Roll Forward]
Real estate acquired in settlement of loans, beginning of period	$ 104,193,000	$ 67,331,000	$ 110,009,000	$ 62,058,000
Plus: New real estate acquired in settlement of loans	6,085,000	52,680,000	15,020,000	73,967,000
Less: Sales of real estate acquired in settlement of loans	(13,502,000)	(8,681,000)	(24,376,000)	(10,399,000)
Less: Write-downs and net loss on sales charged to expense	(10,593,000)	(9,946,000)	(14,470,000)	(24,242,000)
Real estate acquired in settlement of loans, end of period	86,183,000	101,384,000	86,183,000	101,384,000
Number of assets under contract for sale	41		41
Net carrying value of assets under contract for sale	$ 12,900,000		$ 12,900,000