Consolidated Balance Sheets - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020
Assets:
Estimated Fair Value	$ 2,265
Short-term Investments	414	$ 492
Other Investments	690	595
Investments, Total	2,955	3,544
Cash and cash equivalents	17	20
Restricted Cash	5	13
Premiums Receivable, Net	323	370
Reinsurance Recoverables, Including Reinsurance Premium Paid	55	33
Deferred ceded premium	90	70
Subrogation recoverable	2,092	2,156
Derivative assets	76	93
Intangible assets	362	409
Goodwill	46	46
Other assets	68	68
Total assets	12,303	13,220
Liabilities:
Unearned premiums	395	456
Liability for Claims and Claims Adjustment Expense	1,570	1,759
Ceded premiums payable	33	27
Long-term debt	2,230	2,739
Accrued interest payable	576	517
Derivative liabilities	95	114
Other liabilities	133	135
Total liabilities	$ 11,187	$ 12,074
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	257	242
Accumulated other comprehensive income	58	79
Retained earnings	726	759
Treasury Stock, Value	(3)	(1)
Total Ambac Financial Group, Inc. stockholders’ equity	1,038	1,080
Nonredeemable noncontrolling interest	60	60
Total stockholders’ equity	1,098	1,140
Total liabilities, redeemable noncontrolling interest and stockholders’ equity	$ 12,303	$ 13,220
Preferred stock, par value	$ 0.01
Common stock, shares issued	46,477,068	45,865,081
Common stock, shares authorized	130,000,000	130,000,000
Redeemable Noncontrolling Interest, Equity, Carrying Amount	$ 18	$ 7
Xchange
Stockholders’ equity:
Redeemable Noncontrolling Interest, Equity, Carrying Amount		7
Variable Interest Entity [Member]
Assets:
Estimated Fair Value	3,455	3,354
Restricted Cash	2	2
Loans, at fair value	2,718	2,998
Derivative assets	38	41
Other assets	2	2
Total assets	6,216	6,398
Variable interest entity assets:
Loans, at fair value	2,718	2,998
Liabilities:
Long-term debt	4,216	4,493
Derivative liabilities	1,940	1,835
Total liabilities	6,156	6,328
Stockholders’ equity:
Long-term Debt	4,056	4,324
Fixed Income Securities [Member]
Assets:
Estimated Fair Value	1,730	2,317
Collateral Pledged [Member]
Assets:
Estimated Fair Value	120	140
Short-term Investments	105	125
Collateral Pledged [Member] | Fixed Income Securities [Member]
Assets:
Estimated Fair Value	$ 15	$ 15