INCOME TAXES - Summary of Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Deferred tax assets:
Discounting of net reserves for losses and loss expenses	$ 52,992	$ 53,415
Unearned premiums	56,146	53,342
Net unrealized investments losses	71,251	0
Operating and capital loss carryforwards	152,896	85,358
Accruals not currently deductible	42,045	38,294
Tax credits	7,619	2,709
Other deferred tax assets	8,590	5,040
Deferred tax assets before valuation allowance	391,539	238,158
Valuation allowance	(60,069)	(16,918)
Deferred tax assets net of valuation allowance	331,470	221,240
Deferred tax liabilities:
Deferred acquisition costs	(35,211)	(34,845)
Net unrealized investments gains	0	(5,732)
Other investment adjustments and impairments	(20,068)	(18,134)
Intangible assets	(51,993)	(52,722)
Equalization reserves	(2,530)	(2,365)
Acquisition adjustments	(72,351)	(79,464)
Lloyd’s deferred year of account results	(34,068)	(5,114)
Other deferred tax liabilities	(7,029)	(10,004)
Deferred tax liabilities	(223,250)	(208,380)
Net deferred tax assets (liabilities)	$ 108,220	$ 12,860