Variable Interest Entities - Carrying Amounts and Classification of Significant Variable Interests (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Variable Interest Entity [Line Items]
Cash and cash equivalents	$ 9,561,448	$ 6,781,783
Non-marketable and other equity securities	1,200,595	1,213,829
Accrued interest receivable and other assets	2,059,055	1,745,233
Total assets	75,009,640	71,004,903
Other liabilities	2,200,953	2,041,752
Total liabilities	67,826,419	64,383,823
Maximum exposure to loss in unconsolidated VIEs	722,600	689,360
Investments in qualified affordable housing projects, net	500,802	458,476
Consolidated
Variable Interest Entity [Line Items]
Cash and cash equivalents	9,322	7,629
Non-marketable and other equity securities	261,049	270,057
Accrued interest receivable and other assets	1,374	1,117
Total assets	271,745	278,803
Other liabilities	1,677	2,854
Total liabilities	1,677	2,854
Maximum exposure to loss in unconsolidated VIEs	270,100
Unconsolidated
Variable Interest Entity [Line Items]
Cash and cash equivalents	0	0
Non-marketable and other equity securities	722,600	689,360
Accrued interest receivable and other assets	0	0
Total assets	722,600	689,360
Other liabilities	348,272	302,031
Total liabilities	348,272	302,031
Maximum exposure to loss in unconsolidated VIEs	722,600
Unconsolidated | Non-marketable securities
Variable Interest Entity [Line Items]
Maximum exposure to loss in unconsolidated VIEs	$ 722,600	$ 689,360