Variable Interest Entities - Carrying Amounts and Classification of Significant Variable Interests (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Variable Interest Entity [Line Items]
Cash and cash equivalents	$ 17,674,763	$ 6,781,783
Non-marketable and other equity securities	1,802,235	1,213,829
Accrued interest receivable and other assets	3,205,825	1,745,233
Total assets	115,511,007	71,004,903
Other liabilities	3,971,974	2,041,752
Total liabilities	107,077,516	64,383,823
Investments in Affordable Housing Projects [Abstract]
Investments in qualified affordable housing projects	616,188	458,476
Related other liabilities of unfunded credit commitments	370,208	302,031
Variable Interest Entity, Primary Beneficiary
Variable Interest Entity [Line Items]
Cash and cash equivalents	14,859	7,629
Non-marketable and other equity securities	422,049	270,057
Accrued interest receivable and other assets	937	1,117
Total assets	437,845	278,803
Other liabilities	1,410	2,854
Total liabilities	1,410	2,854
Maximum Exposure to Loss in Unconsolidated VIEs	436,400
Variable Interest Entity, Not Primary Beneficiary
Variable Interest Entity [Line Items]
Cash and cash equivalents	0	0
Non-marketable and other equity securities	858,617	689,360
Accrued interest receivable and other assets	0	0
Total assets	858,617	689,360
Other liabilities	370,208	302,031
Total liabilities	370,208	302,031
Maximum Exposure to Loss in Unconsolidated VIEs	858,617	689,360
Non-marketable securities | Variable Interest Entity, Not Primary Beneficiary
Variable Interest Entity [Line Items]
Maximum Exposure to Loss in Unconsolidated VIEs	$ 858,617	$ 689,360