Variable Interest Entities - Assets and Liabilities Related to Non-consolidated VIEs and Maximum Exposure to Losses (Details) - USD ($) $ in Millions	Sep. 30, 2021	Dec. 31, 2020
Variable Interest Entity
Total Assets	$ 207,731	$ 204,680
Total Liabilities	185,207	181,569
CDC investments | Variable Interest Entity, Not Primary Beneficiary
Variable Interest Entity
Total Assets	1,670	1,546
Total Liabilities	538	478
Maximum Exposure	1,670	1,546
Private equity investments | Variable Interest Entity, Not Primary Beneficiary
Variable Interest Entity
Total Assets	129	117
Total Liabilities	0	0
Maximum Exposure	237	200
Loans provided to VIEs | Variable Interest Entity, Not Primary Beneficiary
Variable Interest Entity
Total Assets	2,986	2,420
Total Liabilities	0	0
Maximum Exposure	4,517	3,649
Lease pool entities | Variable Interest Entity, Not Primary Beneficiary
Variable Interest Entity
Total Assets	71	73
Total Liabilities	0	0
Maximum Exposure	$ 71	$ 73