Variable Interest Entities - Assets and Liabilities Related to Non-consolidated VIEs and Maximum Exposure to Losses (Details) - USD ($) $ in Millions	Jun. 30, 2021	Dec. 31, 2020
Variable Interest Entity
Total Assets	$ 205,390	$ 204,680
Total Liabilities	182,464	181,569
CDC investments | Variable Interest Entity, Not Primary Beneficiary
Variable Interest Entity
Total Assets	1,668	1,546
Total Liabilities	519	478
Maximum Exposure	1,668	1,546
Private equity investments | Variable Interest Entity, Not Primary Beneficiary
Variable Interest Entity
Total Assets	117	117
Total Liabilities	0	0
Maximum Exposure	208	200
Loans provided to VIEs | Variable Interest Entity, Not Primary Beneficiary
Variable Interest Entity
Total Assets	2,872	2,420
Total Liabilities	0	0
Maximum Exposure	4,268	3,649
Lease pool entities | Variable Interest Entity, Not Primary Beneficiary
Variable Interest Entity
Total Assets	75	73
Total Liabilities	0	0
Maximum Exposure	$ 75	$ 73