Other Noninterest Expense (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011
Components of other expense
Insurance expense	$ 1,597	$ 502
Ad valorem and franchise taxes	2,207	1,036
Printing and supplies	2,471	573
Public relations and contributions	2,179	382
Travel expense	1,584	387
Other real estate owned expense, net	2,433	1,441
Tax credit investment amortization	1,513
Other miscellaneous expense	10,583	3,158
Total other noninterest expense	$ 24,567	$ 7,479