Variable Interest Entities - Carrying Amounts and Classification of Significant Variable Interests (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Variable Interest Entity [Line Items]
Cash and cash equivalents	$ 6,781,783	$ 3,571,539	$ 2,923,075	$ 2,545,750
Non-marketable and other equity securities	1,213,829	941,104
Accrued interest receivable and other assets	1,745,233	951,261
Total assets	71,004,903	56,927,979
Other liabilities	2,041,752	1,006,359
Total liabilities	64,383,823	51,663,136
Investments in Affordable Housing Projects [Abstract]
Investments in qualified affordable housing projects	458,476	318,575
Related other liabilities of unfunded credit commitments	302,031	205,685
Variable Interest Entity, Primary Beneficiary
Variable Interest Entity [Line Items]
Cash and cash equivalents	7,629	9,058
Non-marketable and other equity securities	270,057	221,646
Accrued interest receivable and other assets	1,117	228
Total assets	278,803	230,932
Other liabilities	2,854	919
Total liabilities	2,854	919
Maximum Exposure to Loss in Unconsolidated VIEs	275,900
Variable Interest Entity, Not Primary Beneficiary
Variable Interest Entity [Line Items]
Cash and cash equivalents	0	0
Non-marketable and other equity securities	689,360	568,272
Accrued interest receivable and other assets	0	0
Total assets	689,360	568,272
Other liabilities	302,031	205,685
Total liabilities	302,031	205,685
Maximum Exposure to Loss in Unconsolidated VIEs	689,360	568,272
Variable Interest Entity, Not Primary Beneficiary | Non-marketable securities
Variable Interest Entity [Line Items]
Maximum Exposure to Loss in Unconsolidated VIEs	$ 689,360	$ 568,272