ACCUMULATED OTHER COMPREHENSIVE LOSS - Schedule of Accumulated Other Comprehensive Loss (Details) - USD ($) $ in Thousands		3 Months Ended		6 Months Ended
		Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
BALANCE		$ 1,131,300	$ 952,468	$ 1,099,914	$ 912,714
Other comprehensive gain (loss) before reclassification				(5,961)	(101)
Reclassification to net income	[1]			1,018	2,348
TOTAL OTHER COMPREHENSIVE (LOSS) INCOME		(1,283)	1,237	(4,943)	2,247
BALANCE		1,165,309	991,616	1,165,309	991,616
Unrealized gain (loss) on available-for-sale securities [Member]
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
BALANCE				(142)	91
Other comprehensive gain (loss) before reclassification				(5,551)	(32)
Reclassification to net income	[1]			0	0
TOTAL OTHER COMPREHENSIVE (LOSS) INCOME				(5,551)	(32)
BALANCE		(5,693)	59	(5,693)	59
Net unrealized gain (loss) on retirement plan [Member]
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
BALANCE	[2]			(18,019)	(36,075)
Other comprehensive gain (loss) before reclassification	[2]			0	0
Reclassification to net income	[1],[2]			1,018	2,348
TOTAL OTHER COMPREHENSIVE (LOSS) INCOME	[2]			1,018	2,348
BALANCE	[2]	(17,001)	(33,727)	(17,001)	(33,727)
Change in cumulative foreign currency translation adjustment [Member]
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
BALANCE				(74)	(35)
Other comprehensive gain (loss) before reclassification				(410)	(69)
Reclassification to net income	[1]			0	0
TOTAL OTHER COMPREHENSIVE (LOSS) INCOME				(410)	(69)
BALANCE		(484)	(104)	(484)	(104)
Accumulated Other Comprehensive Loss [Member]
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
BALANCE		(21,895)	(35,009)	(18,235)	(36,019)
TOTAL OTHER COMPREHENSIVE (LOSS) INCOME		(1,283)	1,237	(4,943)	2,247
BALANCE		$ (23,178)	$ (33,772)	$ (23,178)	$ (33,772)

[1] The Company reclassified amortization of prior service cost and actuarial loss for its retirement plan from accumulated other comprehensive loss to net income of $1.0 million and $2.3 million for the six months ended June 30, 2022 and 2021, respectively.

[2] Refer to Note 17: Supplemental Executive Retirement Plan.