Revenue From Contracts With Customers - Disaggregation of Revenue (Details) - USD ($) $ in Thousands	3 Months Ended			9 Months Ended
	Sep. 30, 2021	Jun. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Disaggregation of Revenue [Line Items]
Total interest income	$ 290,082	$ 280,505	$ 265,908	$ 843,924	$ 831,315
Service charges on deposit accounts	3,407	3,452	2,570	9,793	7,232
Other commissions and fees	11,792	10,704	10,541	31,654	30,373
Leased equipment income	10,943	10,847	9,900	33,144	34,188
Gain on sale of loans and leases	0	1,422	35	1,561	468
Gain on sale of securities	515	0	5,270	616	13,167
Other income	24,688	13,946	9,936	59,777	20,782
Total noninterest income	51,345	$ 40,371	38,252	136,545	106,210
Revenues	341,427		304,160	980,469	937,525
Service charges on deposit accounts	6,073		6,087	18,493	18,581
Interest Income
Disaggregation of Revenue [Line Items]
Revenues				843,924	831,315
Service charges on deposit accounts	0		0	0	0
Service charges on deposit accounts
Disaggregation of Revenue [Line Items]
Revenues				9,793	7,232
Service charges on deposit accounts	3,407		2,570	9,793	7,232
Other commissions and fees
Disaggregation of Revenue [Line Items]
Revenues				31,654	30,373
Service charges on deposit accounts	2,680		3,228	8,140	10,388
Leased equipment income
Disaggregation of Revenue [Line Items]
Revenues				33,144	34,188
Service charges on deposit accounts	0		0	0	0
Gain on sale of loans
Disaggregation of Revenue [Line Items]
Revenues				1,561	468
Service charges on deposit accounts	0		0	0	0
Gain on sale of securities
Disaggregation of Revenue [Line Items]
Revenues				616	13,167
Service charges on deposit accounts	0		0	0	0
Other income
Disaggregation of Revenue [Line Items]
Revenues				59,777	20,782
Service charges on deposit accounts	(14)		289	560	961
Noninterest Income
Disaggregation of Revenue [Line Items]
Revenues				136,545	106,210
Service charges on deposit accounts	$ 6,073		$ 6,087	$ 18,493	$ 18,581