Variable Interest Entities - Carrying Amounts and Classification of Significant Variable Interests (Details) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Variable Interest Entity [Line Items]
Cash and cash equivalents	$ 14,202,106	$ 6,781,783
Non-marketable and other equity securities	1,270,578	1,213,829
Accrued interest receivable and other assets	2,240,990	1,745,233
Total assets	85,730,985	71,004,903
Other liabilities	2,623,407	2,041,752
Total liabilities	78,262,672	64,383,823
Maximum exposure to loss in unconsolidated VIEs	726,879	689,360
Investments in qualified affordable housing projects, net	533,205	458,476
Consolidated
Variable Interest Entity [Line Items]
Cash and cash equivalents	9,363	7,629
Non-marketable and other equity securities	274,685	270,057
Accrued interest receivable and other assets	607	1,117
Total assets	284,655	278,803
Other liabilities	1,447	2,854
Total liabilities	1,447	2,854
Maximum exposure to loss in unconsolidated VIEs	283,200
Unconsolidated
Variable Interest Entity [Line Items]
Cash and cash equivalents	0	0
Non-marketable and other equity securities	726,879	689,360
Accrued interest receivable and other assets	0	0
Total assets	726,879	689,360
Other liabilities	332,935	302,031
Total liabilities	332,935	302,031
Maximum exposure to loss in unconsolidated VIEs	726,900
Unconsolidated | Non-marketable securities
Variable Interest Entity [Line Items]
Maximum exposure to loss in unconsolidated VIEs	$ 726,879	$ 689,360