FAIR VALUE MEASUREMENT - Assets and Liabilities Measured At Fair Value (Details) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Assets:
Cash equivalents—Money market funds	$ 199,279	$ 246,425
Equity securities, at fair value	32,328	41,046
Available-for-sale debt securities	10,608	10,484
Trading securities held in a "rabbi trust"	519	496
Total assets	242,734	298,451
Liabilities:
Deferred compensation accrual "rabbi trust"	537	513
Total liabilities	537	513
Level 1
Assets:
Cash equivalents—Money market funds	199,279	246,425
Equity securities, at fair value	0	0
Available-for-sale debt securities	0	0
Trading securities held in a "rabbi trust"	519	496
Total assets	199,798	246,921
Liabilities:
Deferred compensation accrual "rabbi trust"	537	513
Total liabilities	537	513
Level 2
Assets:
Cash equivalents—Money market funds	0	0
Equity securities, at fair value	0	0
Available-for-sale debt securities	0	0
Trading securities held in a "rabbi trust"	0	0
Total assets	0	0
Liabilities:
Deferred compensation accrual "rabbi trust"	0	0
Total liabilities	0	0
Level 3
Assets:
Cash equivalents—Money market funds	0	0
Equity securities, at fair value	32,328	41,046
Available-for-sale debt securities	10,608	10,484
Trading securities held in a "rabbi trust"	0	0
Total assets	42,936	51,530
Liabilities:
Deferred compensation accrual "rabbi trust"	0	0
Total liabilities	$ 0	$ 0