Consolidated Balance Sheets - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Assets:
Estimated Fair Value	$ 3,314
Short-term investments, at fair value	653	$ 430
Other Investments	478	391
Total investments	3,792	3,937
Cash and cash equivalents	24	63
Restricted Cash	55	19
Premium receivables	416	495
Reinsurance recoverable on paid and unpaid losses	26	23
Deferred ceded premium	82	61
Subrogation recoverable	2,029	1,933
Derivative assets	75	59
Income Taxes Receivable, Current	11	47
Insurance intangible asset	427	719
Other assets	95	138
Total assets	13,320	14,589
Liabilities:
Unearned premiums	518	630
Loss and loss expense reserves	1,548	1,826
Ceded premiums payable	29	33
Deferred Income Tax Liabilities, Net	32	40
Long-term debt	2,822	2,929
Accrued interest payable	441	376
Derivative liabilities	90	77
Other liabilities	93	64
Variable interest entity liabilities:
Total liabilities	11,783	12,956
Stockholders’ equity:
Preferred stock, par value $0.01 per share; 20,000,000 shares authorized shares; issued and outstanding shares—none	0	0
Common stock, par value $0.01 per share; 130,000,000 shares authorized; issued shares: 45,571,743 and 45,365,170	0	0
Additional paid-in capital	232	219
Accumulated other comprehensive income (loss)	42	(49)
Retained earnings	1,203	1,421
Treasury stock, shares at cost: 16,343 and 28,892	0	0
Total Ambac Financial Group, Inc. stockholders’ equity	1,477	1,592
Noncontrolling interest	60	41
Total stockholders’ equity	1,536	1,633
Total liabilities and stockholders’ equity	13,320	14,589
Variable Interest Entity [Member]
Assets:
Estimated Fair Value	3,121	2,737
Restricted Cash	2	1
Loans, at fair value	3,108	4,288
Derivative assets	52	66
Other assets	3	1
Total assets	6,286	7,093
Variable interest entity assets:
Loans, at fair value	3,108	4,288
Liabilities:
Long-term debt	4,554	5,269
Accrued interest payable	1	1
Derivative liabilities	1,657	1,712
Variable interest entity liabilities:
Total liabilities	6,212	6,981
Fixed Income Securities [Member]
Assets:
Estimated Fair Value	2,577	3,116
Collateral Pledged [Member] | Fixed Income Securities [Member]
Assets:
Estimated Fair Value	$ 85	$ 0