Statements of Cash Flows (Details) (USD $) In Thousands, unless otherwise specified	6 Months Ended
	Jun. 30, 2013		Jun. 30, 2012
Statements of Cash Flows [Abstract]
Income taxes paid	$ 13,920		$ 19,283
Interest expense paid on deposits and borrowings	12,580		17,323
Noncash transfers from loans to foreclosed properties	20,700	[1]	17,962	[1]
Assets acquired in business combination	1,849,929		234,960
Liabilities assumed in business combination	$ 1,821,066		$ 209,322

[1] Includes transfers from covered loans to foreclosed properties