Other Noninterest Expense - Summary of Other Noninterest Expense (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Other Income and Expenses [Abstract]
Lending and other client related processing costs	$ 7,194	$ 7,502	$ 23,155	$ 21,442
Correspondent bank fees	3,581	3,657	11,400	10,970
Investment banking activities	2,835	1,864	13,633	9,918
Trade order execution costs	2,806	2,615	8,165	7,959
Data processing services	3,984	3,066	10,945	8,624
Telephone	2,342	2,466	6,458	7,629
Dues and publications	1,159	1,055	3,199	3,439
Postage and supplies	538	720	2,117	2,168
Other	13,114	11,161	38,831	32,910
Total other noninterest expense	$ 37,553	$ 34,106	$ 117,903	$ 105,059