Consolidated Balance Sheets (Parenthetical) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2014	Dec. 31, 2013
Securities available-for-sale, amortized cost	$ 1,644,805	$ 1,680,491
Less: Unearned income on loans	(62,724)	(68,282)
Other real estate owned covered by FDIC loss share	30,552	35,927
Common stock, par value
Common stock, shares authorized	63,033	63,033
Common stock, shares outstanding	52,600	51,265
Covered Loans [Member]
Allowance for losses on covered loans	(20,129)	(20,174)
Other real estate owned covered by FDIC loss share	$ 14,712	$ 12,093