Allowance for Credit Losses (Allowance for Credit Losses Methodology) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Allowance for credit losses on loans and leases
Balance, beginning of period	$ 261,111	$ 279,887	$ 248,412	$ 328,401
(Recapture) provision for credit losses for loans and leases	28,542	(16,132)	53,025	(33,381)
Charge-offs	(10,392)	(10,373)	(29,181)	(48,367)
Recoveries	3,804	4,178	10,809	10,907
Net recoveries (charge-offs)	(6,588)	(6,195)	(18,372)	(37,460)
Balance, end of period	283,065	257,560	283,065	257,560
Reserve for unfunded commitments
Balance, beginning of period	12,823	14,539	12,767	20,286
(Recapture) provision for credit losses on unfunded commitments	(970)	(2,787)	(914)	(8,534)
Balance, end of period	11,853	11,752	11,853	11,752
Total allowance for credit losses	294,918	269,312	294,918	269,312
Commercial real estate
Allowance for credit losses on loans and leases
Balance, beginning of period	88,983	128,951	99,075	141,710
(Recapture) provision for credit losses for loans and leases	(3,563)	(20,141)	(13,745)	(33,199)
Charge-offs	0	(916)	(8)	(1,086)
Recoveries	123	120	221	589
Net recoveries (charge-offs)	123	(796)	213	(497)
Balance, end of period	85,543	108,014	85,543	108,014
Reserve for unfunded commitments
Balance, beginning of period	7,351	10,094	8,461	15,360
(Recapture) provision for credit losses on unfunded commitments	(1,994)	(3,273)	(3,104)	(8,539)
Balance, end of period	5,357	6,821	5,357	6,821
Total allowance for credit losses	90,900	114,835	90,900	114,835
Commercial
Allowance for credit losses on loans and leases
Balance, beginning of period	131,455	121,390	117,573	150,864
(Recapture) provision for credit losses for loans and leases	26,762	2,719	52,058	4,180
Charge-offs	(9,459)	(8,521)	(26,352)	(44,228)
Recoveries	2,842	3,346	8,321	8,118
Net recoveries (charge-offs)	(6,617)	(5,175)	(18,031)	(36,110)
Balance, end of period	151,600	118,934	151,600	118,934
Reserve for unfunded commitments
Balance, beginning of period	2,232	2,145	2,028	2,190
(Recapture) provision for credit losses on unfunded commitments	579	440	783	395
Balance, end of period	2,811	2,585	2,811	2,585
Total allowance for credit losses	154,411	121,519	154,411	121,519
Residential
Allowance for credit losses on loans and leases
Balance, beginning of period	36,586	25,296	29,068	27,964
(Recapture) provision for credit losses for loans and leases	4,307	1,703	11,603	(1,212)
Charge-offs	(4)	0	(171)	(70)
Recoveries	249	281	638	598
Net recoveries (charge-offs)	245	281	467	528
Balance, end of period	41,138	27,280	41,138	27,280
Reserve for unfunded commitments
Balance, beginning of period	2,735	1,710	1,957	1,661
(Recapture) provision for credit losses on unfunded commitments	304	247	1,082	296
Balance, end of period	3,039	1,957	3,039	1,957
Total allowance for credit losses	44,177	29,237	44,177	29,237
Consumer & Other
Allowance for credit losses on loans and leases
Balance, beginning of period	4,087	4,250	2,696	7,863
(Recapture) provision for credit losses for loans and leases	1,036	(413)	3,109	(3,150)
Charge-offs	(929)	(936)	(2,650)	(2,983)
Recoveries	590	431	1,629	1,602
Net recoveries (charge-offs)	(339)	(505)	(1,021)	(1,381)
Balance, end of period	4,784	3,332	4,784	3,332
Reserve for unfunded commitments
Balance, beginning of period	505	590	321	1,075
(Recapture) provision for credit losses on unfunded commitments	141	(201)	325	(686)
Balance, end of period	646	389	646	389
Total allowance for credit losses	$ 5,430	$ 3,721	$ 5,430	$ 3,721