Variable Interest Entities - Summary of Variable Interest Entities Information (Details) - USD ($) $ in Millions	Jun. 30, 2021	Dec. 31, 2020
Variable Interest Entity [Line Items]
Total Assets	$ 181,115	$ 170,336
Total Liabilities	163,174	152,355
Variable Interest Entity, Not Primary Beneficiary
Variable Interest Entity [Line Items]
Total Assets	369	351
Total Liabilities	1	1
Variable Interest Entity, Not Primary Beneficiary | LIHTC investments
Variable Interest Entity [Line Items]
Total Assets	6,599	6,914
Total Liabilities	2,232	2,765
Maximum Exposure to Loss	1,885	1,823
Variable Interest Entity, Not Primary Beneficiary | Principal Investments, Indirect
Variable Interest Entity [Line Items]
Total Assets	10,828	10,899
Total Liabilities	179	168
Maximum Exposure to Loss	$ 66	$ 78