PARENT COMPANY FINANCIALS ONLY (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012		Dec. 31, 2011		Dec. 31, 2010	Dec. 31, 2009
Assets:
Prepaid income taxes
Total assets	5,756,985		4,970,240
Liabilities and stockholders’ equity
Other Borrowings
Junior subordinated debentures	74,127		61,857
Other liabilities	89,933		86,668
Total liabilities	5,227,665		4,501,183
Stockholders’ equity	529,320		469,057		436,472	412,649
Total liabilities and stockholders' equity	5,756,985		4,970,240
Parent Company [Member]
Assets:
Cash	18,535	[1]	26,391	[1]
Investments in subsidiaries	600,808	[2]	513,561	[2]
Prepaid income taxes	161
Deferred tax asset	4,602		4,471
Deferred stock issuance costs	267		169
Total assets	624,373		544,592
Liabilities and stockholders’ equity
Dividends payable			4,086
Other Borrowings	12,000
Junior subordinated debentures	74,127		61,857
Accrued income taxes			41
Derivative instruments	8,834	[1]	9,489	[1]
Other liabilities	92		62
Total liabilities	95,053		75,535
Stockholders’ equity	529,320		469,057
Total liabilities and stockholders' equity	624,373		544,592
Consolidation, Eliminations [Member]
Assets:
Investments in subsidiaries	$ 598,608		$ 511,703

[1] Entire balance eliminates in consolidation.

[2] $598,608 and $511,703 eliminate in consolidation at December 31, 2012 and 2011, respectively.