Outstanding Exposure - Amortization Schedule of Puerto Rico BIG Net Par Outstanding and BIG Net Debt Service Outstanding (Details) - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020
Estimated BIG Net Par Amortization [Abstract]
Total net par outstanding	$ 236,392	$ 234,153
Estimated BIG Net Debt Service Amortization [Abstract]
Total	367,360	366,233
Puerto Rico
Estimated BIG Net Par Amortization [Abstract]
2022 (January 1 - March 31)	0
2022 (April 1 - June 30)	0
2022 (July 1 - September 30)	176
2022 (October 1 - December 31)	0
Subtotal 2022	176
2023	206
2024	222
2025	223
2026	214
2027-2031	953
2037-2041	1,253
2037-2041	320
2042	5
Total net par outstanding	3,572	$ 3,725
Estimated BIG Net Debt Service Amortization [Abstract]
2022 (January 1 - March 31)	88
2022 (April 1 - June 30)	2
2022 (July 1 - September 30)	264
2022 (October 1 - December 31)	3
Subtotal 2022	357
2023	378
2024	383
2025	373
2026	353
2027-2031	1,494
2032-2036	1,543
2037-2041	364
2042	5
Total	$ 5,250