PARENT COMPANY ONLY CONDENSED FINANCIAL INFORMATION - Cash Flows (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Cash flows from operating activities
Net earnings	$ 27,402	$ 26,279	$ 20,596
Adjustments:
Stock based compensation	749	663	592
Net cash provided by operating activities	42,521	32,046	28,214
Cash flows from investing activities
Net cash used in investing activities	(165,768)	(17,740)	(108,734)
Cash flows from financing activities
Purchase of treasury stock	(16,927)	(10,140)	(4,265)
Exercise of stock options	638	925	327
Dividends paid	(8,487)	(8,065)	(7,031)
Net cash provided by financing activities	384,324	4,898	60,602
Net change in cash and cash equivalents	261,077	19,204	(19,918)
Cash and cash equivalents at beginning of period	90,714	71,510	91,428
Cash and cash equivalents at end of period	351,791	90,714	71,510
Parent Company
Cash flows from operating activities
Net earnings	27,402	26,279	20,596
Adjustments:
Equity in undistributed subsidiary earnings	(29,757)	(5,097)	(13,378)
Stock based compensation	749	663	592
Change in other assets	18	85	127
Change in other liabilities	(673)	503	557
Net cash provided by operating activities	(2,261)	22,433	8,494
Cash flows from investing activities
Cash paid in connection with acquisitions	0	0	(6,423)
Net cash used in investing activities	0	0	(6,423)
Cash flows from financing activities
Proceeds of borrowings	40,000	0	0
Repayments of borrowings	(19,000)	(2,000)	(1,000)
Purchase of treasury stock	(16,927)	(10,140)	(4,265)
Exercise of stock options	638	925	327
Dividends paid	(8,487)	(8,065)	(7,031)
Net cash provided by financing activities	(3,776)	(19,280)	(11,969)
Net change in cash and cash equivalents	(6,037)	3,153	(9,898)
Cash and cash equivalents at beginning of period	7,264	4,111	14,009
Cash and cash equivalents at end of period	$ 1,227	$ 7,264	$ 4,111