Parent Company Financial Information (Condensed Balance Sheets) (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Assets
Interest-earning deposits	$ 389,353	$ 202,925
Total cash and cash equivalents	513,926	294,289	514,130	305,074
Other assets	113,967	126,928
Total Assets	4,906,335	4,785,945
Liabilities and Shareholders’ Equity
Other liabilities	68,598	67,069
Total liabilities	4,142,327	4,026,607
Shareholders’ equity	764,008	759,338	706,878	528,139
Total liabilities and shareholders' equity	4,906,335	4,785,945
Parent [Member]
Assets
Cash and due from banking subsidiaries	1,729	3,220
Interest-earning deposits	84,915	72,014
Total cash and cash equivalents	86,644	75,234	159,173	83,006
Other assets	649	510
Total Assets	764,267	759,721
Liabilities and Shareholders’ Equity
Other liabilities	259	383
Total liabilities	259	383
Shareholders’ equity	764,008	759,338
Total liabilities and shareholders' equity	764,267	759,721
Banking Subsidiaries [Member] | Parent [Member]
Assets
Investment in subsidiaries	$ 676,974	$ 683,977