INVESTMENTS - Equity Securities (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2025	Dec. 31, 2024
Debt and Equity Securities, FV-NI [Line Items]
Cost	$ 538,378	$ 520,743
Gross unrealized gains	86,375	127,218
Gross unrealized losses	(50,374)	(68,687)
Fair value	574,379	579,274
Common stocks
Debt and Equity Securities, FV-NI [Line Items]
Cost	3,061	3,061
Gross unrealized gains	64	65
Gross unrealized losses	(509)	(488)
Fair value	2,616	2,638
Preferred stocks
Debt and Equity Securities, FV-NI [Line Items]
Cost	5,843	5,843
Gross unrealized gains	157	136
Gross unrealized losses	(112)	(112)
Fair value	5,888	5,867
Exchange-traded funds
Debt and Equity Securities, FV-NI [Line Items]
Cost	235,124	188,771
Gross unrealized gains	83,685	126,477
Gross unrealized losses	(4,301)	(1,206)
Fair value	314,508	314,042
Bond mutual funds
Debt and Equity Securities, FV-NI [Line Items]
Cost	294,350	323,068
Gross unrealized gains	2,469	540
Gross unrealized losses	(45,452)	(66,881)
Fair value	$ 251,367	$ 256,727