Off-Balance Sheet Arrangements, Guarantees and Other Commitments - Summary of Commercial and Standby Letters of Credit (Details) $ in Thousands	Dec. 31, 2019 USD ($)
Other Commitments [Line Items]
Expires In One Year or Less	$ 2,679,736
Expires After One Year	98,825
Total Amount Outstanding	2,778,561
Maximum Amount of Future Payments	2,778,561
Financial standby letters of credit
Other Commitments [Line Items]
Expires In One Year or Less	2,566,623
Expires After One Year	79,207
Total Amount Outstanding	2,645,830
Maximum Amount of Future Payments	2,645,830
Performance standby letters of credit
Other Commitments [Line Items]
Expires In One Year or Less	105,993
Expires After One Year	19,618
Total Amount Outstanding	125,611
Maximum Amount of Future Payments	125,611
Commercial letters of credit
Other Commitments [Line Items]
Expires In One Year or Less	7,120
Expires After One Year	0
Total Amount Outstanding	7,120
Maximum Amount of Future Payments	$ 7,120