Consolidated Balance Sheets (Parenthetical) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Securities available-for-sale, amortized cost	$ 969,359	$ 987,560
Other real estate owned covered by FDIC loss share	26,987	51,019
Common stock, par value	$ 0	$ 0
Common stock, shares authorized	63,033	63,033
Common stock, outstanding		39,506
Noncovered Loans [Member]
Unearned income on loans	(7,767)	(16,217)
Allowance for losses	(52,244)	(53,041)
Other real estate owned covered by FDIC loss share	10,676	22,893
Covered Loans [Member]
Allowance for losses	(30,056)	(4,944)
Other real estate owned covered by FDIC loss share	$ 16,311	$ 28,126