Consolidated Balance Sheets - USD ($) $ in Millions	Dec. 31, 2023	Dec. 31, 2022
Assets:
Available-for-sale Securities	$ 1,710	$ 1,395
Debt Securities, Trading and Available-for-Sale	27	59
Short-term Investments	426	507
Other Investments	475	568
Investments, Total	2,664	2,593
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents	28	44
Restricted Cash	12	14
Premiums Receivable, Net	290	269
Reinsurance Recoverables, Including Reinsurance Premium Paid	195	115
Deferred ceded premium	204	124
Deferred Policy Acquisition Cost	11	3
Subrogation recoverable	137	271
Derivative assets	26	27
Intangible assets, less accumulated amortization	307	326
Goodwill	70	61
Other assets	129	112
Total assets	8,428	7,973
Liabilities:
Unearned premiums	422	372
Liability for Claims and Claims Adjustment Expense	893	805
Ceded premiums payable	90	39
Capitalized Contract Cost, Net	6	5
Long-term debt	508	639
Accrued interest payable	475	427
Derivative liabilities	35	38
Other liabilities	199	201
Liabilities	$ 6,997	$ 6,647
Preferred Stock, Shares Outstanding	0	0
Preferred stock, shares authorized	20,000,000	20,000,000
Stockholders’ equity:
Preferred Stock, Value, Issued	$ 0	$ 0
Common Stock, Value, Issued	0	0
Additional paid-in capital	292	274
Accumulated other comprehensive income (loss)	(160)	(253)
Retained earnings	1,246	1,245
Treasury Stock, Value	(17)	(15)
Total Ambac Financial Group, Inc. stockholders’ equity	1,362	1,252
Nonredeemable noncontrolling interest	53	53
Total stockholders’ equity	$ 1,415	$ 1,305
Preferred stock, par value	$ 0.01
Common stock, shares issued	46,659,144	46,658,990
Common stock, shares authorized	130,000,000	130,000,000
Redeemable Noncontrolling Interest, Equity, Carrying Amount	$ 17	$ 20
Total liabilities, redeemable noncontrolling interest and stockholders’ equity	$ 8,428	$ 7,973
Treasury Stock, Common, Shares	1,463,774	1,685,233
Variable Interest Entity [Member]
Assets:
Available-for-sale Securities	$ 2,167	$ 1,967
Restricted Cash	246	17
Loans, at fair value	1,663	1,829
Derivative and other assets	318	241
Derivative assets	226	239
Other assets	92	2
Total assets	4,394	4,054
Variable interest entity assets:
Loans, at fair value	1,663	1,829
Liabilities:
Long-term debt	2,967	3,107
Derivative liabilities	1,197	1,048
Other Sundry Liabilities, Current	240
Other liabilities	5	5
Liabilities	4,404	4,160
Stockholders’ equity:
Long-term Debt	2,710	2,788
Collateral Pledged [Member]
Assets:
Available-for-sale Securities	27	64
Short-term Investments	$ 27	$ 64