Statements of Cash Flows (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2013		Mar. 31, 2012
Statements of Cash Flows [Abstract]
Income taxes paid	$ 480		$ 465
Interest expense paid on deposits and borrowings	5,023		8,560
Noncash transfers from loans to foreclosed properties	8,886	[1]	8,864	[1]
Assets acquired in business combination	1,851,878		234,960
Liabilities assumed in business combination	$ 1,821,066		$ 209,322

[1] Includes transfers from covered loans to foreclosed properties.