Variable Interest Entities - Carrying Amounts and Classification of Significant Variable Interests (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Variable Interest Entity [Line Items]
Cash and cash equivalents	$ 21,254,859	$ 17,674,763
Non-marketable and other equity securities	1,857,761	1,802,235
Accrued interest receivable and other assets	4,184,114	3,205,825
Total assets	142,346,620	115,511,007
Other liabilities	6,411,705	3,971,974
Total liabilities	132,225,841	107,077,516
Maximum exposure to loss in unconsolidated VIEs	867,187	858,617
Investments in qualified affordable housing projects, net	616,997	616,188
Consolidated
Variable Interest Entity [Line Items]
Cash and cash equivalents	11,392	14,859
Non-marketable and other equity securities	450,537	422,049
Accrued interest receivable and other assets	13,094	937
Total assets	475,023	437,845
Other liabilities	11,041	1,410
Total liabilities	11,041	1,410
Maximum exposure to loss in unconsolidated VIEs	464,000
Unconsolidated
Variable Interest Entity [Line Items]
Cash and cash equivalents	0	0
Non-marketable and other equity securities	867,187	858,617
Accrued interest receivable and other assets	0	0
Total assets	867,187	858,617
Other liabilities	372,516	370,208
Total liabilities	372,516	370,208
Non-marketable securities | Unconsolidated
Variable Interest Entity [Line Items]
Maximum exposure to loss in unconsolidated VIEs	$ 867,187	$ 858,617