CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (UNAUDITED) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Statement of Comprehensive Income [Abstract]
NET INCOME	$ 41,502	$ 40,541	$ 91,472	$ 92,228
OTHER COMPREHENSIVE (LOSS) INCOME, NET OF TAX:
Unrealized (loss) gain on available-for-sale securities, net of tax of $450, $7, $1,547 and $9, respectively	(1,616)	26	(5,551)	(32)
Amortization of prior service cost and actuarial loss for retirement plan included in net periodic pension costs, net of tax of $142, $334, $285 and $669, respectively	509	1,174	1,018	2,348
Change in cumulative foreign currency translation adjustment	(176)	37	(410)	(69)
TOTAL OTHER COMPREHENSIVE (LOSS) INCOME	(1,283)	1,237	(4,943)	2,247
COMPREHENSIVE INCOME	$ 40,219	$ 41,778	$ 86,529	$ 94,475