PARENT COMPANY STATEMENTS, Condensed Statements of Condition (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Assets [Abstract]
Cash and cash equivalents	$ 211,834	$ 221,038	$ 173,857	$ 153,210
Investment in and advances to [Abstract]
Other assets	223,498	249,488
Total assets	10,607,295	10,746,198	8,666,437
Liabilities and shareholders' equity [Abstract]
Accrued interest and other liabilities	157,459	180,567
Borrowings	97,939	122,814
Shareholders' equity	1,713,783	1,635,315	1,198,100	1,140,647
Total liabilities and shareholders' equity	10,607,295	10,746,198
Parent Company [Member]
Assets [Abstract]
Cash and cash equivalents	116,133	84,460	$ 151,127	$ 97,317
Investment securities	3,452	4,322
Investment in and advances to [Abstract]
Bank subsidiary	1,522,109	1,511,780
Non-bank subsidiaries	182,617	169,341
Other assets	8,957	9,150
Total assets	1,833,268	1,779,053
Liabilities and shareholders' equity [Abstract]
Accrued interest and other liabilities	21,546	20,924
Borrowings	97,939	122,814
Shareholders' equity	1,713,783	1,635,315
Total liabilities and shareholders' equity	$ 1,833,268	$ 1,779,053