Variable Interest Entities - Summary of Variable Interest Entities Information (Details) - USD ($) $ in Millions	Sep. 30, 2021	Dec. 31, 2020
Variable Interest Entity [Line Items]
Total Assets	$ 187,035	$ 170,336
Total Liabilities	169,525	152,355
Variable Interest Entity, Not Primary Beneficiary
Variable Interest Entity [Line Items]
Total Assets	3,166	351
Total Liabilities	1	1
Variable Interest Entity, Not Primary Beneficiary | LIHTC investments
Variable Interest Entity [Line Items]
Total Assets	7,389	6,914
Total Liabilities	2,861	2,765
Maximum Exposure to Loss	1,882	1,823
Variable Interest Entity, Not Primary Beneficiary | Principal Investments, Indirect
Variable Interest Entity [Line Items]
Total Assets	10,199	10,899
Total Liabilities	189	168
Maximum Exposure to Loss	$ 61	$ 78