Statements of Cash Flows (Details) (USD $) In Thousands	6 Months Ended
	Jun. 30, 2011	Jun. 30, 2010
Statements of Cash Flows [Abstract]
Income taxes paid	$ 22,144	$ 24,215
Interest expense paid on deposits and borrowings	23,858	32,654
Noncash transfers from loans to foreclosed properties	32,878	34,045
Transfer of long-term FHLB advance to short-term	0	75,000
Assets acquired in business combination	207,243	0
Liabilities assumed in business combination	$ 228,236	$ 0