Other Real Estate Owned and Property Acquired in Settlement of Loans (Real Estate Owned) (Details) (USD $)	12 Months Ended
	Dec. 31, 2012 assets	Dec. 31, 2011 assets
Reposessed Assets [Roll Forward]
Real estate acquired in settlement of loans, beginning of period	$ 110,009,000	$ 62,058,000
Plus: New real estate acquired in settlement of loans	32,565,000	132,546,000
Less: Sales of real estate acquired in settlement of loans	(57,991,000)	(58,782,000)
Less: Write-downs and net loss on sales charged to expense	(21,787,000)	(44,249,000)
Real estate acquired in settlement of loans, end of period	62,796,000	110,009,000
Number of assets under contract for sale	35	25
Net carrying value of assets under contract for sale	22,000,000	21,300,000
Granite Corp. [Member]
Reposessed Assets [Roll Forward]
Plus: Real estate acquired in BOGC acquisition	$ 0	$ 18,436,000