Loans Receivable, Net - ACL Activity (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Allowance for loan and lease losses
Balance at beginning of period	$ 124,490	$ 131,239	$ 129,568
Impact of adopting CECL	3,720
Acquisitions	49
Provision for credit losses	37,637	57	9,953
Charge-offs	(13,808)	(15,178)	(17,807)
Recoveries	6,155	8,372	9,525
Balance at end of period	158,243	124,490	131,239
Residential Real Estate
Allowance for loan and lease losses
Balance at beginning of period	10,111	10,631	10,798
Impact of adopting CECL	3,584
Acquisitions	0
Provision for credit losses	(4,131)	(163)	474
Charge-offs	(21)	(608)	(728)
Recoveries	61	251	87
Balance at end of period	9,604	10,111	10,631
Commercial Real Estate
Allowance for loan and lease losses
Balance at beginning of period	69,496	72,448	68,515
Impact of adopting CECL	10,533
Acquisitions	49
Provision for credit losses	9,324	(2,704)	4,343
Charge-offs	(3,497)	(2,460)	(3,469)
Recoveries	1,094	2,212	3,059
Balance at end of period	86,999	69,496	72,448
Other Commercial
Allowance for loan and lease losses
Balance at beginning of period	36,129	38,160	39,303
Impact of adopting CECL	(13,759)
Acquisitions	0
Provision for credit losses	29,812	(23)	1,916
Charge-offs	(4,860)	(4,189)	(5,045)
Recoveries	1,811	2,181	1,986
Balance at end of period	49,133	36,129	38,160
Home Equity
Allowance for loan and lease losses
Balance at beginning of period	4,937	5,811	6,204
Impact of adopting CECL	3,400
Acquisitions	0
Provision for credit losses	(27)	(863)	(471)
Charge-offs	(384)	(90)	(210)
Recoveries	256	79	288
Balance at end of period	8,182	4,937	5,811
Consumer and Other
Allowance for loan and lease losses
Balance at beginning of period	3,817	4,189	4,748
Impact of adopting CECL	(38)
Acquisitions	0
Provision for credit losses	2,659	3,810	3,691
Charge-offs	(5,046)	(7,831)	(8,355)
Recoveries	2,933	3,649	4,105
Balance at end of period	$ 4,325	$ 3,817	$ 4,189