Allowance for Credit Losses (Allowance for Credit Losses Methodology) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Allowance for credit losses on loans and leases
Balance, beginning of period	$ 248,564	$ 311,283	$ 248,412	$ 328,401
(Recapture) provision for credit losses for loans and leases	18,787	(17,775)	24,483	(17,249)
Charge-offs	(9,879)	(17,079)	(18,789)	(37,994)
Recoveries	3,639	3,458	7,005	6,729
Net recoveries (charge-offs)	(6,240)	(13,621)	(11,784)	(31,265)
Balance, end of period	261,111	279,887	261,111	279,887
Reserve for unfunded commitments
Balance, beginning of period	12,918	19,760	12,767	20,286
(Recapture) provision for credit losses on unfunded commitments	(95)	(5,221)	56	(5,747)
Balance, end of period	12,823	14,539	12,823	14,539
Total allowance for credit losses	273,934	294,426	273,934	294,426
Commercial real estate
Allowance for credit losses on loans and leases
Balance, beginning of period	91,638	154,475	99,075	141,710
(Recapture) provision for credit losses for loans and leases	(2,720)	(25,484)	(10,182)	(13,058)
Charge-offs	(8)	(129)	(8)	(170)
Recoveries	73	89	98	469
Net recoveries (charge-offs)	65	(40)	90	299
Balance, end of period	88,983	128,951	88,983	128,951
Reserve for unfunded commitments
Balance, beginning of period	8,738	15,668	8,461	15,360
(Recapture) provision for credit losses on unfunded commitments	(1,387)	(5,574)	(1,110)	(5,266)
Balance, end of period	7,351	10,094	7,351	10,094
Total allowance for credit losses	96,334	139,045	96,334	139,045
Commercial
Allowance for credit losses on loans and leases
Balance, beginning of period	121,072	128,838	117,573	150,864
(Recapture) provision for credit losses for loans and leases	16,484	5,964	25,296	1,461
Charge-offs	(9,035)	(16,093)	(16,893)	(35,707)
Recoveries	2,934	2,681	5,479	4,772
Net recoveries (charge-offs)	(6,101)	(13,412)	(11,414)	(30,935)
Balance, end of period	131,455	121,390	131,455	121,390
Reserve for unfunded commitments
Balance, beginning of period	1,620	1,801	2,028	2,190
(Recapture) provision for credit losses on unfunded commitments	612	344	204	(45)
Balance, end of period	2,232	2,145	2,232	2,145
Total allowance for credit losses	133,687	123,535	133,687	123,535
Residential
Allowance for credit losses on loans and leases
Balance, beginning of period	31,946	21,090	29,068	27,964
(Recapture) provision for credit losses for loans and leases	4,424	3,997	7,296	(2,915)
Charge-offs	0	0	(167)	(70)
Recoveries	216	209	389	317
Net recoveries (charge-offs)	216	209	222	247
Balance, end of period	36,586	25,296	36,586	25,296
Reserve for unfunded commitments
Balance, beginning of period	2,193	1,288	1,957	1,661
(Recapture) provision for credit losses on unfunded commitments	542	422	778	49
Balance, end of period	2,735	1,710	2,735	1,710
Total allowance for credit losses	39,321	27,006	39,321	27,006
Consumer & Other
Allowance for credit losses on loans and leases
Balance, beginning of period	3,908	6,880	2,696	7,863
(Recapture) provision for credit losses for loans and leases	599	(2,252)	2,073	(2,737)
Charge-offs	(836)	(857)	(1,721)	(2,047)
Recoveries	416	479	1,039	1,171
Net recoveries (charge-offs)	(420)	(378)	(682)	(876)
Balance, end of period	4,087	4,250	4,087	4,250
Reserve for unfunded commitments
Balance, beginning of period	367	1,003	321	1,075
(Recapture) provision for credit losses on unfunded commitments	138	(413)	184	(485)
Balance, end of period	505	590	505	590
Total allowance for credit losses	$ 4,592	$ 4,840	$ 4,592	$ 4,840