CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Statement of Comprehensive Income [Abstract]
Net Income (Loss)	$ 222,079	$ 203,011	$ 210,061
OTHER COMPREHENSIVEINCOME (LOSS), NET OF TAX:
Unrealized gain (loss) on available-for-sale securities, net of tax of none, none and $65, respectively	411	8,745	(7,745)
Employee benefit plan:
Actuarial gain on retirement plan, net of tax of $178, ($2,168) and ($1,667), respectively	(559)	7,207	5,971
Amortization of prior service cost, actuarial loss and curtailment charge for retirement plan included in net periodic pension costs, net of tax of ($84), ($299) and ($569), respectively	261	996	2,037
Net change in employee benefit plan	(298)	8,203	8,008
Change in cumulative foreign currency translation adjustment	(82)	418	(480)
TOTAL OTHER COMPREHENSIVE INCOME (LOSS)	31	17,366	(217)
COMPREHENSIVE INCOME	$ 222,110	$ 220,377	$ 209,844