DISCONTINUED OPERATION - Narrative (Details) - USD ($) $ / shares in Units, $ in Thousands		12 Months Ended
	Jun. 04, 2024	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022	Mar. 31, 2024	Apr. 30, 2013
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Common stock, par value (in dollars per share)						$ 0.01
Preferred stock, shares outstanding (in shares)		0	0
Nonredeemable noncontrolling interest		$ 197,755	$ 52,958
NOL allocated amount		$ 1,663,087
Dividend Rate on Auction Rate Preferred Shares		11.448%
Auction Market Preferred Shares | American Acorn Corporation
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Preferred stock, dividend rate, basis spread on reference rate				200.00%
Ambac Assurance Corporation | Discontinued Operations, Held-for-Sale or Disposed of by Sale
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Aggregate consideration	$ 420,000
Sale consummation extension period	90 days
Curable period for breach	60 days
Contingent termination fee payable	$ 22,000
Period from termination for alternative acquisition	12 months
Contingent reimbursement payable	$ 6,000
Number of securities called by warrants as percentage of fully diluted shares of common stock					9.90%
Warrants exercise price (in dollars per share)	$ 18.50
Warrants term	6 years 6 months
Purchase of co-investment, amount	$ 62,000
Purchase of co-investment, percent per annum	7.50%
Carrying amount of net assets held-for-sale		$ 962,637
Gain on purchase of AMPS		0	0	$ 1,131
Period for preferred stock auction occurrence	28 days
Loss on disposal		(570,145)	$ 0	$ 0
Reclassification from AOCI at closing		(175,278)
U. S. Federal Net Operating Tax | Interest Expense
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
NOL allocated amount		$ 110,494
Ambac Assurance Corporation
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Preferred stock, shares outstanding (in shares)		4,596	4,596
Preferred stock, liquidation preference, value		$ 114,900	$ 114,900
Nonredeemable noncontrolling interest		$ 50,918
5.1% Surplus Notes, General Account, Due 2020 | Ambac Assurance Corporation
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Debt instrument, interest rate		5.10%
Long-term debt, gross		$ 519,235
Long-term debt		$ 503,139
Secured Debt | Ambac UK
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Debt instrument, interest rate		0.00%
Long-term debt, gross		$ 40,600
Long-term debt		$ 18,079
Debt discount amortization rate		7.40%