PARENT ONLY CONDENSED FINANCIAL STATEMENTS - Parent Only Condensed Balance Sheets (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Assets
Cash and cash equivalents	$ 86,552	$ 67,578	$ 62,485	$ 61,320
Securities available for sale	1,007,540	925,279
Total assets	4,080,257	3,385,408
Liabilities
Subordinated debentures	41,239	41,239
Borrowings	18,333
Other liabilities	19,323	14,183
Total liabilities	3,630,763	3,004,048
Shareholders' equity	449,494	381,360	360,662	305,526
Total liabilities and shareholders' equity	4,080,257	3,385,408
Parent Company
Assets
Cash and cash equivalents	10,366	14,846	$ 6,322	$ 11,667
Securities available for sale	130	149
Investment in subsidiaries	494,158	403,981
Other assets	8,396	9,586
Total assets	513,050	428,562
Liabilities
Subordinated debentures	41,239	41,239
Borrowings	18,333
Other liabilities	3,984	5,963
Total liabilities	63,556	47,202
Shareholders' equity	449,494	381,360
Total liabilities and shareholders' equity	$ 513,050	$ 428,562