Consolidated Balance Sheets (USD $) In Thousands, unless otherwise specified	Mar. 31, 2012	Dec. 31, 2011
ASSETS
Cash and due from banks	$ 93,904	$ 91,364
Interest-earning deposits with banks	297,553	202,925
Total cash and cash equivalents	391,457	294,289
Securities available for sale at fair value (amortized cost of $987,560 and $743,928, respectively)	999,213	1,028,110
Federal Home Loan Bank stock at cost	22,215	22,215
Loans held for sale	2,066	2,148
Loans, net	2,821,148	2,827,259
FDIC loss sharing asset	159,061	175,071
Interest receivable	16,037	15,287
Premises and equipment, net	113,071	107,899
Other real estate owned ($28,126 and $14,443 covered by FDIC loss share, respectively)	41,174	51,019
Goodwill	115,554	115,554
Core deposit intangible, net	19,016	20,166
Other assets	115,420	126,928
Total Assets	4,815,432	4,785,945
LIABILITIES AND SHAREHOLDERS' EQUITY
Noninterest-bearing	1,159,308	1,156,610
Interest-bearing	2,706,137	2,658,919
Total deposits	3,865,445	3,815,529
Federal Home Loan Bank advances	114,715	119,009
Securities sold under agreements to repurchase	25,000	25,000
Other liabilities	57,569	67,069
Total liabilities	4,062,729	4,026,607
Commitments and contingent liabilities
Shareholders' equity:
Authorized shares	63,033	63,033
Common Stock Shares Issued And Outstanding	39,670	39,506
Common Stock (no par value)	579,894	579,136
Retained earnings	149,348	155,069
Accumulated other comprehensive income	23,461	25,133
Total shareholders' equity	752,703	759,338
Total Liabilities and Shareholders' Equity	4,815,432	4,785,945
Noncovered Loans [Member]
ASSETS
Loans held for sale	2,066	2,148
Loans, excluding covered loans, net of unearned income of ($16,217) and ($3,490), respectively	2,371,818	2,348,371
Less: allowance for loan and lease losses	52,283	53,041
Loans, net	2,319,535	2,295,330
Other real estate owned ($28,126 and $14,443 covered by FDIC loss share, respectively)	16,744	22,893
Covered Loans [Member]
ASSETS
Less: allowance for loan and lease losses	20,504	4,944
Loans, net	501,613	531,929
Other real estate owned ($28,126 and $14,443 covered by FDIC loss share, respectively)	$ 24,430	$ 28,126