Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Statement Of Cash Flows [Abstract]
Net cash from operating activities	$ 16,413	$ 25,554
Cash flows used for investing activities:
Maturities, paydowns and calls of securities, available-for-sale	18,055	16,987
Purchases of securities, available-for-sale	(18,149)	(20,901)
Sale of equity securities		247
Net loan originations	217	(34,044)
Proceeds from sale of other real estate owned properties	118
Proceeds from sale of premises and equipment		10
Premises and equipment purchases	(163)	(135)
Net cash provided by (used for) investing activities	78	(37,836)
Cash flows from financing activities:
Net change in short-term FHLB advances		(84,500)
Increase in deposits	286,509	313,175
Increase in securities sold under repurchase agreements	599	4,025
Purchase of treasury shares	(3,976)	(11,095)
Common dividends paid	(1,907)	(1,835)
Net cash provided by financing activities	281,225	219,770
Increase in cash and cash equivalents	297,716	207,488
Cash and cash equivalents at beginning of period	139,522	48,535
Cash and cash equivalents at end of period	437,238	256,023
Cash paid during the period for:
Interest	1,923	2,885
Supplemental cash flow information:
Transfer of loans held for sale to portfolio	46
Change in fair value of swap asset	9,091	(14,085)
Change in fair value of swap liability	(9,111)	$ 14,085
Securities purchased not settled	$ 1,967