Parent Company Financial Statements - Schedule of Condensed Statements of Cash Flows (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2021	Sep. 30, 2021	Jun. 30, 2021	Mar. 31, 2021	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2021	Dec. 31, 2020
CASH FLOWS FROM OPERATING ACTIVITIES
Net income	$ 8,510	$ 8,138	$ 8,239	$ 8,065	$ 7,261	$ 7,285	$ 6,854	$ 6,745	$ 32,952	$ 28,145
Adjustments to reconcile net income to net cash provided by (used in) operating activities:
Other operating activities, net									(1,066)	429
Net cash provided by (used in) operating activities									62,264	12,798
CASH FLOWS FROM INVESTING ACTIVITIES
Net cash provided by (used in) investing activities									(284,678)	(316,256)
CASH FLOWS FROM FINANCING ACTIVITIES
Repurchase of common stock									(7,878)	(122)
Proceeds from exercise of stock options									0	8
Cash dividends									(2,033)	(1,759)
Net cash provided by (used in) financing activities									560,077	617,367
Net change in cash and cash equivalents									337,663	313,909
Cash and cash equivalents - beginning of year				447,201				133,292	447,201	133,292
Cash and cash equivalents - end of year	784,864				447,201				784,864	447,201
Parent Company
CASH FLOWS FROM OPERATING ACTIVITIES
Net income									32,952	28,145
Adjustments to reconcile net income to net cash provided by (used in) operating activities:
Undistributed earnings of subsidiaries									(33,485)	(29,026)
Other operating activities, net									181	358
Net cash provided by (used in) operating activities									(352)	(523)
CASH FLOWS FROM INVESTING ACTIVITIES
Net cash provided by (used in) investing activities									0	0
CASH FLOWS FROM FINANCING ACTIVITIES
Repurchase of common stock									(7,878)	(122)
Proceeds from exercise of stock options									0	8
Cash dividends									(2,033)	(1,759)
Net cash provided by (used in) financing activities									(9,911)	(1,873)
Net change in cash and cash equivalents									(10,263)	(2,396)
Cash and cash equivalents - beginning of year				$ 23,868				$ 26,264	23,868	26,264
Cash and cash equivalents - end of year	$ 13,605				$ 23,868				$ 13,605	$ 23,868