PARENT COMPANY ONLY CONDENSED FINANCIAL INFORMATION (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Assets:
Cash and cash equivalents	$ 94,747	$ 113,838	$ 104,558	$ 51,730
Other assets	34,329	38,911
Total Assets	4,430,002	4,054,570
Liabilities and stockholders' equity:
Subordinated debentures	78,641	78,502
Junior subordinated debentures		15,244
Total Liabilities	4,000,802	3,646,583
Total Stockholders' Equity	429,200	407,987	341,128	175,118
Total Liabilities and Stockholders' Equity	4,430,002	4,054,570
Parent Company
Assets:
Cash and cash equivalents	7,858	29,049	$ 25,475	$ 610
Other assets	210	228
Investment in the Bank	500,896	474,035
Total Assets	508,964	503,312
Liabilities and stockholders' equity:
Subordinated debentures	78,641	78,502
Junior subordinated debentures	0	15,244
Other liabilities	1,123	1,579
Total Liabilities	79,764	95,325
Total Stockholders' Equity	429,200	407,987
Total Liabilities and Stockholders' Equity	$ 508,964	$ 503,312