Noninterest Income - Lending Related Fees (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Disaggregation of Revenue [Line Items]
Lending related fees	$ 49,920	$ 41,949	$ 43,265
Unused commitment fees
Disaggregation of Revenue [Line Items]
Lending related fees	34,829	32,452	34,110
Other
Disaggregation of Revenue [Line Items]
Lending related fees	$ 15,091	$ 9,497	$ 9,155