Condensed Financial Information (parent company only) - Balance Sheet (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
ASSETS
Goodwill	$ 188,948	$ 141,375	$ 141,357
Other assets	28,997	14,455
TOTAL ASSETS	5,437,262	4,304,821
LIABILITIES
Total Borrowings	523,264	367,089
Other Liabilities	45,836	37,272
Total Liabilities	4,802,339	3,752,585
Stockholders' Equity	634,923	552,236	514,467	454,408
TOTAL LIABILITIES AND STOCKHOLDERS' EQUITY	5,437,262	4,304,821
Parent [Member]
ASSETS
Cash	13,228	35,160
Investment in Subsidiaries	745,818	633,971
Goodwill	448	448
Other assets	8,695	6,638
TOTAL ASSETS	768,189	676,217
LIABILITIES
Total Borrowings	126,702	111,702
Other Liabilities	6,564	12,279
Total Liabilities	133,266	123,981
Stockholders' Equity	634,923	552,236
TOTAL LIABILITIES AND STOCKHOLDERS' EQUITY	$ 768,189	$ 676,217