INCOME TAXES - Effective tax rate - (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Effective income tax rate differs from the statutory rate
U.S. statutory rate (as a percent)	21.00%	21.00%	21.00%
State income taxes, net (as a percent)	2.40%	2.10%	2.20%
Exempt municipal bond interest (as a percent)			(0.10%)
Foreign income tax rates (as a percent)	0.20%	1.00%	(0.10%)
Income tax credits and adjustments (as a percent)	(0.60%)	(1.40%)	0.50%
Adjustment of deferred tax balances (as a percent)	0.60%	(0.20%)
Reserve for uncertain tax benefits (as a percent)		(0.80%)	0.40%
Other, net (as a percent)	0.20%	1.00%	0.20%
Effective income tax rate (as a percent)	23.80%	22.70%	24.10%
Unrecognized tax benefits	$ 3,133	$ 3,011	$ 3,678
Portion of unrecognized tax benefits that, if recognized, would favorably affect annual effective income tax rate	1,547	1,468
Interest and penalties included in liability for uncertain tax positions	282	340
Reconciliation of the beginning and ending balances of the total amounts of unrecognized tax benefits
Unrecognized tax benefits at the beginning of the period	3,011	3,678	3,339
Increases in tax positions for the current year	700	377	1,164
Reductions in tax positions for lapse of statute of limitations	(578)	(501)	(576)
Reductions in tax positions for settlements and payments		(308)	(249)
Increases (decreases) in prior period unrecognized tax benefits due to change in judgment		(235)
Unrecognized tax benefits at the end of the period	3,133	$ 3,011	$ 3,678
Spain
Effective income tax rate differs from the statutory rate
Tax benefits of foreign subsidiary tax loss carry forwards expiring in 2026	286
Tax benefits of foreign subsidiary tax loss carry forwards expiring in 2027	61
Tax benefits of foreign subsidiary tax loss carry forwards expiring in 2028	182
Tax benefits of foreign subsidiary tax loss carry forwards expiring in 2029	103
Tax benefits of foreign subsidiary tax loss carry forwards expiring in 2030	314
Tax benefits of foreign subsidiary tax loss carry forwards expiring in 2031	418
Tax benefits of foreign subsidiary tax loss carry forwards expiring in 2032	315
Tax benefits of foreign subsidiary tax loss carry forwards expiring in 2033	127
Tax benefits of foreign subsidiary tax loss carry forwards expiring in 2034	440
Tax benefits of foreign subsidiary tax loss carry forwards expiring in 2035	556
Tax benefits of foreign subsidiary tax loss carry forwards expiring in 2036	805
Tax benefits of foreign subsidiary tax loss carry forwards expiring in 2037	412
Tax benefits of foreign subsidiary tax loss carry forwards expiring in 2038	197
Tax benefits of foreign subsidiary tax loss carry forwards expiring in 2039	$ 160