Loans Receivable, Net - Summary of Loans Receivable (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Jun. 30, 2023	Dec. 31, 2022	Sep. 30, 2022	Jun. 30, 2022	Dec. 31, 2021
Summary of Loans Receivable
Loans receivable	$ 16,135,046		$ 15,246,812
Allowance for credit losses	(192,271)	$ (189,385)	(182,283)	$ (178,191)	$ (172,963)	$ (172,665)
Loans receivable, net	15,942,775		15,064,529
Net deferred origination (fees) costs included in loans receivable	(26,121)		(25,882)
Net purchase accounting (discounts) premiums included in loans receivable	(14,619)		(17,832)
Accrued interest receivable on loans	72,017		54,971
Residential real estate
Summary of Loans Receivable
Loans receivable	1,653,777		1,446,008
Allowance for credit losses	(21,697)	(20,847)	(19,683)	(18,422)	(16,959)	(16,458)
Commercial real estate
Summary of Loans Receivable
Loans receivable	10,292,446		9,797,047
Allowance for credit losses	(130,852)	(129,598)	(125,816)	(124,399)	(121,259)	(117,901)
Other commercial
Summary of Loans Receivable
Loans receivable	2,916,785		2,799,668
Allowance for credit losses	(21,771)	(21,797)	(21,454)	(21,364)	(21,079)	(24,703)
Home equity
Summary of Loans Receivable
Loans receivable	869,963		822,232
Allowance for credit losses	(11,624)	(11,053)	(10,759)	(9,562)	(9,333)	(8,566)
Other consumer
Summary of Loans Receivable
Loans receivable	402,075		381,857
Allowance for credit losses	$ (6,327)	$ (6,090)	$ (4,571)	$ (4,444)	$ (4,333)	$ (5,037)