Allowance for Credit Losses (Allowance for Credit Losses Methodology) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019	Jan. 01, 2020
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Balance, beginning of period	$ 157,629
Impact of adoption of CECL	157,629
Provision for credit losses for loans and leases	105,502
Charge-offs	24,455
Recoveries	2,745
Net (charge-offs) recoveries	21,710
Balance, end of period	291,420
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance		$ 144,871
Charge-offs		(17,152)
Recoveries		3,469
Provision	118,085	13,684
Ending balance		144,872
Accounting Standards Update 2016-13 [Member]
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Impact of adoption of CECL	49,999		$ 207,628
Balance, end of period	49,999
Commercial real estate
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Balance, beginning of period	50,847
Impact of adoption of CECL	99,778
Provision for credit losses for loans and leases	43,608
Charge-offs	0
Recoveries	246
Net (charge-offs) recoveries	(246)
Balance, end of period	99,778
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance		47,904
Charge-offs		(2,151)
Recoveries		337
Provision		1,751
Ending balance		47,841
Commercial real estate | Accounting Standards Update 2016-13 [Member]
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Impact of adoption of CECL	5,077		55,924
Balance, end of period	5,077
Commercial
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Balance, beginning of period	73,820
Impact of adoption of CECL	146,607
Provision for credit losses for loans and leases	49,673
Charge-offs	22,608
Recoveries	1,713
Net (charge-offs) recoveries	20,895
Balance, end of period	146,607
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance		63,957
Charge-offs		(13,210)
Recoveries		2,354
Provision		11,269
Ending balance		64,370
Commercial | Accounting Standards Update 2016-13 [Member]
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Impact of adoption of CECL	44,009		117,829
Balance, end of period	44,009
Residential
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Balance, beginning of period	24,714
Impact of adoption of CECL	34,251
Provision for credit losses for loans and leases	7,185
Charge-offs	11
Recoveries	264
Net (charge-offs) recoveries	(253)
Balance, end of period	34,251
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance		22,034
Charge-offs		(135)
Recoveries		155
Provision		119
Ending balance		22,173
Residential | Accounting Standards Update 2016-13 [Member]
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Impact of adoption of CECL	2,099		26,813
Balance, end of period	2,099
Consumer & other, net
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Balance, beginning of period	8,248
Impact of adoption of CECL	10,784
Provision for credit losses for loans and leases	5,036
Charge-offs	1,836
Recoveries	522
Net (charge-offs) recoveries	1,314
Balance, end of period	10,784
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance		10,976
Charge-offs		(1,656)
Recoveries		623
Provision		545
Ending balance		$ 10,488
Consumer & other, net | Accounting Standards Update 2016-13 [Member]
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Impact of adoption of CECL	(1,186)		$ 7,062
Balance, end of period	$ (1,186)