Other Noninterest Expense - Summary of Other Noninterest Expense (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Other Income and Expenses [Abstract]
Lending and other client related processing costs	$ 6,803	$ 8,763	$ 15,961	$ 13,940
Correspondent bank fees	3,833	3,569	7,819	7,313
Investment banking activities	7,768	3,869	10,798	8,054
Trade order execution costs	2,614	2,828	5,359	5,344
Data processing services	3,507	2,659	6,961	5,558
Telephone	1,889	2,422	4,116	5,163
Dues and publications	910	860	2,040	2,384
Postage and supplies	723	678	1,579	1,448
Other	11,600	11,769	25,717	21,749
Total other noninterest expense	$ 39,647	$ 37,417	$ 80,350	$ 70,953