Revenue Recognition - Summary of Noninterest Income Segregated by Revenue Streams In-Scope and Out-of-Scope of Topic 606 (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Disaggregation of Revenue [Line Items]
Service Charges on Deposit Accounts	$ 24,910	$ 30,074	$ 28,811
Fees, Exchange, and Other Service Charges	47,056	57,893	57,482
Annuity and Insurance	3,362	6,934	5,822
Other	30,434	27,489	21,233
Noninterest Income	184,409	183,338	168,923
Accounting Standards Update 2014-09
Disaggregation of Revenue [Line Items]
Noninterest Income	184,409	183,338	168,923
Accounting Standards Update 2014-09 | Noninterest Income In Scope of Topic 606
Disaggregation of Revenue [Line Items]
Trust and Asset Management	43,456	44,233	43,877
Service Charges on Deposit Accounts	11,715	13,042	13,165
Fees, Exchange, and Other Service Charges	36,005	46,381	46,350
Annuity and Insurance	3,249	6,813	5,615
Other	8,626	9,633	9,652
Noninterest Income	103,051	120,102	118,659
Accounting Standards Update 2014-09 | Noninterest Income Out of Scope of Topic 606
Disaggregation of Revenue [Line Items]
Noninterest Income	$ 81,358	$ 63,236	$ 50,264