Allowance for Loan and Lease Losses - Schedule of the Impaired and Non-Impaired Loans and Leases, By Loan and Leases Class (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Jun. 30, 2021	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Dec. 31, 2019
Recorded investment in loans and leases by portfolio segment
Individually evaluated for impairment, allowance	$ 2,618		$ 2,311
Collectively evaluated for impairment, allowance	99,897		112,068
Total allowance for loan and lease losses	102,515	$ 106,474	114,379	$ 119,971	$ 119,553	$ 61,082
Individually evaluated, loans and leases	42,112		47,646
Collectively evaluated, loans and leases	6,889,582		7,221,907
Total	6,931,694		7,269,553
Commercial real estate loans
Recorded investment in loans and leases by portfolio segment
Individually evaluated for impairment, allowance	87		183
Collectively evaluated for impairment, allowance	72,293		79,949
Total allowance for loan and lease losses	72,380	74,009	80,132	87,220	90,011	30,285
Individually evaluated, loans and leases	16,954		14,159
Collectively evaluated, loans and leases	3,892,057		3,809,667
Total	3,909,011		3,823,826
Commercial
Recorded investment in loans and leases by portfolio segment
Individually evaluated for impairment, allowance	2,441		2,020
Collectively evaluated for impairment, allowance	24,749		27,478
Total allowance for loan and lease losses	27,190	28,364	29,498	28,578	24,938	24,826
Individually evaluated, loans and leases	17,438		24,727
Collectively evaluated, loans and leases	1,852,248		2,250,172
Total	1,869,686		2,274,899
Consumer
Recorded investment in loans and leases by portfolio segment
Individually evaluated for impairment, allowance	90		108
Collectively evaluated for impairment, allowance	2,855		4,641
Total allowance for loan and lease losses	2,945	$ 4,101	4,749	$ 4,173	$ 4,604	$ 5,971
Individually evaluated, loans and leases	7,720		8,760
Collectively evaluated, loans and leases	1,145,277		1,162,068
Total	$ 1,152,997		$ 1,170,828