CONSOLIDATED STATEMENTS OF CASH FLOWS - (UNAUDITED) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2018
Operating activities
Net income			$ 28,534	$ 26,614
Adjustments to reconcile net income to net cash from
Depreciation and amortization of premises, and equipment			1,451	922
Net accretion of securities, loans, deposits, and other			(2,537)	(670)
Unrealized (gain) on equity securities			(147)
Amortization of investment in affordable housing tax credits			675	483
Amortization of intangible assets			3,637	2,404
Provision for credit losses	$ 824	$ 1,695	1,731	2,579	$ 4,469
Stock-based compensation			544	446
Deferred tax benefit			(438)	(1,573)
Gain on sale of securities	(7)		(7)
Gain on sale of loans	(813)	(1,125)	(6,131)	(5,025)
Gain on sale of OREO	(11)		(11)
Gain on sale of fixed assets			(6)
Increase in cash surrender value of life insurance			(580)	(598)
Loans originated and purchased for sale			(102,887)	(338,129)
Proceeds from loans sold			347,623	170,179
Other items			(4,470)	(1,597)
Net cash provided by (used in) operating activities			266,981	(143,965)
Investing activities
Increase in interest-earning deposits			(349)
Securities available for sale:
Purchases			(112,656)	(59,288)
Maturities, prepayments and calls			109,977	35,541
Sales			6,136
Securities held to maturity:
Maturities, prepayments and calls			1,205
Redemption of Federal Home Loan Bank stock			1,751
Purchase of Federal Home Loan Bank stock and other equity securities, net			(8,641)	(8,008)
Purchase of investment in qualified affordable housing projects				(4,500)
Net increase in loans			(45,735)	(212,688)
Proceeds from sales of OREO			819
Proceeds from sale of fixed assets			17
Purchases of premises and equipment			(954)	(2,105)
Net cash used in investing activities			(48,430)	(251,048)
Financing activities
Net (decrease) increase in demand deposits and savings accounts			(77,905)	52,658
Net increase in time deposits			185,771	175,025
Net (decrease) increase in FHLB advances			(284,500)	185,000
Cash dividends paid			(6,030)	(4,234)
Common stock repurchased, net of repurchased costs			(3,190)
Exercise of stock options			2,694	8,069
Net cash (used in) provided by financing activities			(183,160)	416,518
Net increase (decrease) in cash and cash equivalents			35,391	21,505
Cash and cash equivalents at beginning of period			147,685	150,048	150,048
Cash and cash equivalents at end of period	$ 183,076	$ 171,553	183,076	171,553	$ 147,685
Cash paid during the period:
Interest paid			24,600	2,778
Taxes paid			13,010	7,785
Non-cash investing and financing activities:
Transfer from loans to other real estate owned			974
Transfer of loans to held for sale			63,422	138,045
Net change in unrealized holding (loss) gain on securities available for sale			$ 1,669	$ (1,073)