Schedule II - Condensed Financial Information of Registrant (Parent Company Only) Schedule II - Condensed Financial Information of Registrant - Income Taxes (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2024 USD ($)
Operating Loss Carryforwards	$ 1,663,087
AFG [Member]
Operating Loss Carryforwards	1,663,087
Ambac Assurance [Member]
Operating Loss Carryforwards	$ 1,952,621
Ambac Assurance [Member] | Minimum [Member]
Operating Loss Carryforwards, Expiration Date	Dec. 31, 2030
Ambac Assurance [Member] | Maximum [Member]
Operating Loss Carryforwards, Expiration Date	Dec. 31, 2042
Interest Expense | U. S. Federal Net Operating Tax
Operating Loss Carryforwards	$ 110,494