Outstanding Insurance Exposure - Schedule of General Obligation and PBA Bonds Activity (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Schedule of Insured Financial Obligations [Line Items]
Net par amount outstanding	$ 236,807	$ 241,802
Vintage GO [Member]
Schedule of Insured Financial Obligations [Line Items]
Net par amount outstanding	669
Total net principal claims paid	383
Total net interest claims paid	$ 147
Base recovery as percent of pre-petition claims	74.90%
2011 GO (Series D, E and PIB) [Member]
Schedule of Insured Financial Obligations [Line Items]
Net par amount outstanding	$ 5
Total net principal claims paid	6
Total net interest claims paid	$ 1
Base recovery as percent of pre-petition claims	73.80%
2011 Go (Series C) [Member]
Schedule of Insured Financial Obligations [Line Items]
Net par amount outstanding	$ 210
Total net principal claims paid	0
Total net interest claims paid	$ 42
Base recovery as percent of pre-petition claims	70.40%
2012 GO [Member]
Schedule of Insured Financial Obligations [Line Items]
Net par amount outstanding	$ 369
Total net principal claims paid	0
Total net interest claims paid	$ 63
Base recovery as percent of pre-petition claims	69.90%
2014 GO [Member]
Schedule of Insured Financial Obligations [Line Items]
Net par amount outstanding	$ 0
Total net principal claims paid	0
Total net interest claims paid	$ 0
Base recovery as percent of pre-petition claims	65.40%
Vintage PBA [Member]
Schedule of Insured Financial Obligations [Line Items]
Net par amount outstanding	$ 140
Total net principal claims paid	32
Total net interest claims paid	$ 24
Base recovery as percent of pre-petition claims	77.60%
2011 PBA [Member]
Schedule of Insured Financial Obligations [Line Items]
Net par amount outstanding	$ 0
Total net principal claims paid	0
Total net interest claims paid	$ 0
Base recovery as percent of pre-petition claims	76.80%
2012 PBA [Member]
Schedule of Insured Financial Obligations [Line Items]
Net par amount outstanding	$ 0
Total net principal claims paid	0
Total net interest claims paid	$ 0
Base recovery as percent of pre-petition claims	72.20%