PARENT COMPANY STATEMENTS, Condensed Balance Sheets (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Assets [Abstract]
Cash and cash equivalents	$ 173,857	$ 153,210	$ 138,396	$ 149,647
Investment in and advances to [Abstract]
Other assets	180,188	170,129
Total assets	8,666,437	8,552,669	7,489,440
Liabilities and shareholders' equity [Abstract]
Accrued interest and other liabilities	144,013	135,102
Borrowings	102,170	102,146
Shareholders' equity	1,198,100	1,140,647	987,904	875,812
Total liabilities and shareholders' equity	8,666,437	8,552,669
Parent Company [Member]
Assets [Abstract]
Cash and cash equivalents	151,127	97,317	$ 106,957	$ 83,783
Investment securities	3,628	3,576
Investment in and advances to [Abstract]
Bank subsidiary	1,116,554	1,117,419
Non-bank subsidiaries	35,566	30,643
Other assets	10,345	9,996
Total assets	1,317,220	1,258,951
Liabilities and shareholders' equity [Abstract]
Accrued interest and other liabilities	16,950	16,158
Borrowings	102,170	102,146
Shareholders' equity	1,198,100	1,140,647
Total liabilities and shareholders' equity	$ 1,317,220	$ 1,258,951