Commitments, Off-Balance Sheet Arrangements, Legal Proceedings and Regulatory Matters, Summary of Lending Related and Other Commitments (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Schedule of lending-related and other commitments [Line Items]
Lending related commitments, fair value	$ 0	$ 0
Summary of lending-related and other commitments
Unfunded Commitments	57,276	21,907
Commitments to extend credit, excluding commitments to originate residential mortgage loans held for sale(a)(b)
Summary of lending-related and other commitments
Lending related commitments	9,582,235	9,024,412
Commercial letters of credit(a)
Summary of lending-related and other commitments
Lending related commitments	6,977	7,081
Standby letters of credit(c)
Summary of lending-related and other commitments
Lending related commitments	252,292	277,969
Standby letters of credit, fair value	$ 2,000	$ 3,000