Loans Receivable, Net - ACL Activity (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Allowance for credit losses
Balance at beginning of period	$ 156,446	$ 150,190	$ 158,243	$ 124,490
Impact of adopting CECL				3,720
Acquisitions				49
Provision for credit losses	(5,723)	13,552	(5,234)	36,296
Charge-offs	(1,700)	(2,668)	(5,946)	(5,235)
Recoveries	2,425	1,435	4,385	3,189
Balance at end of period	151,448	162,509	151,448	162,509
Residential real estate
Allowance for credit losses
Balance at beginning of period	9,018	9,315	9,604	10,111
Impact of adopting CECL				3,584
Acquisitions				0
Provision for credit losses	884	662	302	(3,707)
Charge-offs	0	(1)	(38)	(21)
Recoveries	241	10	275	19
Balance at end of period	10,143	9,986	10,143	9,986
Commercial real estate
Allowance for credit losses
Balance at beginning of period	95,251	70,848	86,999	69,496
Impact of adopting CECL				10,533
Acquisitions				49
Provision for credit losses	1,269	18,309	8,732	8,876
Charge-offs	(41)	(150)	(41)	(180)
Recoveries	118	97	907	330
Balance at end of period	96,597	89,104	96,597	89,104
Other commercial
Allowance for credit losses
Balance at beginning of period	39,385	56,409	49,133	36,129
Impact of adopting CECL				(13,759)
Acquisitions				0
Provision for credit losses	(8,319)	(6,974)	(15,584)	27,159
Charge-offs	(351)	(1,088)	(3,113)	(1,873)
Recoveries	1,268	491	1,547	1,182
Balance at end of period	31,983	48,838	31,983	48,838
Home equity
Allowance for credit losses
Balance at beginning of period	8,068	7,934	8,182	4,937
Impact of adopting CECL				3,400
Acquisitions
Provision for credit losses	(278)	2,174	(367)	1,666
Charge-offs	0	(193)	(45)	(194)
Recoveries	47	47	67	153
Balance at end of period	7,837	9,962	7,837	9,962
Other consumer
Allowance for credit losses
Balance at beginning of period	4,724	5,684	4,325	3,817
Impact of adopting CECL				(38)
Acquisitions				0
Provision for credit losses	721	(619)	1,683	2,302
Charge-offs	(1,308)	(1,236)	(2,709)	(2,967)
Recoveries	751	790	1,589	1,505
Balance at end of period	$ 4,888	$ 4,619	$ 4,888	$ 4,619