Loans Receivable, Net - Summary of Loans Receivable (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Summary of Loans Receivable
Loans receivable	$ 11,122,696	$ 9,512,810
Allowance for credit losses	(158,243)	(124,490)	$ (131,239)	$ (129,568)
Loans receivable, net	10,964,453	9,388,320
Net deferred origination (fees) costs included in loans receivable	(26,709)	(6,964)
Net purchase accounting (discounts) premiums included in loans receivable	(17,091)	(21,574)
Accrued interest receivable on loans	53,538	40,962
Residential Real Estate
Summary of Loans Receivable
Loans receivable	802,508	926,388
Allowance for credit losses	(9,604)	(10,111)	(10,631)	(10,798)
Commercial Real Estate
Summary of Loans Receivable
Loans receivable	6,315,895	5,579,307
Allowance for credit losses	(86,999)	(69,496)	(72,448)	(68,515)
Other Commercial
Summary of Loans Receivable
Loans receivable	3,054,817	2,094,254
Allowance for credit losses	(49,133)	(36,129)	(38,160)	(39,303)
Home Equity
Summary of Loans Receivable
Loans receivable	636,405	617,201
Allowance for credit losses	(8,182)	(4,937)	(5,811)	(6,204)
Consumer and Other
Summary of Loans Receivable
Loans receivable	313,071	295,660
Allowance for credit losses	$ (4,325)	$ (3,817)	$ (4,189)	$ (4,748)