Consolidated Balance Sheets - USD ($) $ in Millions	Mar. 31, 2020	Dec. 31, 2019
Assets:
Fixed income securities, at fair value (amortized cost of $2,367 and $2,450)	$ 3,037
Short-term investments, at fair value (amortized cost of $586 and $653)	586	$ 653
Other investments	363	478
Total investments (net of allowance for credit losses of $0 at March 31, 2020)	3,400	3,792
Cash and cash equivalents	58	24
Restricted Cash	31	55
Premium receivables (net of allowance for credit losses of $14 at March 31, 2020)	403	416
Reinsurance recoverable on paid and unpaid losses	36	26
Deferred ceded premium	79	82
Subrogation recoverable	2,192	2,029
Derivative assets	88	75
Income Taxes Receivable	16	11
Insurance intangible asset	406	427
Other assets	144	95
Total assets	12,777	13,320
Liabilities:
Unearned premiums	507	518
Loss and loss expense reserves	1,797	1,548
Ceded premiums payable	28	29
Long-term debt	2,760	2,822
Accrued interest payable	457	441
Derivative Liability	137	90
Other liabilities	131	93
Total liabilities	11,716	11,783
Stockholders’ equity:
Preferred stock, par value $0.01 per share; 20,000,000 shares authorized; issued and outstanding shares—none	0	0
Common Stock, Value, Issued	0	0
Additional paid-in capital	235	232
Accumulated other comprehensive income	(149)	42
Retained earnings	917	1,203
Treasury stock, shares at cost: 0 and 8,202	(2)	0
Total Ambac Financial Group, Inc. stockholders’ equity	1,002	1,477
Noncontrolling interest	60	60
Total stockholders’ equity	1,062	1,536
Total liabilities and stockholders’ equity	12,777	13,320
Deferred Income Tax Liabilities, Net	26	32
Variable Interest Entity, Primary Beneficiary [Member]
Assets:
Fixed income securities, at fair value (amortized cost of $2,367 and $2,450)	2,928	3,121
Restricted Cash	2	2
Derivative assets	62	52
Other assets	1	3
Total assets	5,925	6,286
Liabilities:
Long-term debt	4,263	4,554
Accrued interest payable	0	1
Derivative Liability	1,610	1,657
Total liabilities	5,873	6,212
Stockholders’ equity:
Financing Receivable, after Allowance for Credit Loss	2,932	3,108
Fixed Income Securities [Member]
Assets:
Fixed income securities, at fair value (amortized cost of $2,367 and $2,450)	2,367	2,577
Collateral Pledged [Member] | Fixed Income Securities [Member]
Assets:
Fixed income securities, at fair value (amortized cost of $2,367 and $2,450)	$ 85	$ 85