STOCKHOLDERS' EQUITY - AOCI Components (Details) - USD ($) $ in Thousands	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Accumulated Other Comprehensive Income
Total after-tax amount	$ 1,314,362	$ 1,242,363	$ 1,151,401	$ 929,067
Accumulated Other Comprehensive Income
Accumulated Other Comprehensive Income
Total pre-tax amount	337	5,817	9,566
Total after-tax amount	272	4,324	7,103	$ 3,699
Unrecognized Net Periodic Benefit Credit
Accumulated Other Comprehensive Income
Total pre-tax amount	5,660	6,816	9,287
Total after-tax amount	4,203	5,061	6,896
Interest Rate Swap
Accumulated Other Comprehensive Income
Total pre-tax amount		1,710	3,526
Total after-tax amount		1,263	2,604
Foreign Currency Translation
Accumulated Other Comprehensive Income
Total pre-tax amount	(5,323)	(2,709)	(3,247)
Total after-tax amount	$ (3,931)	$ (2,000)	$ (2,397)