Segment Information (Summary Of Financial Information By Reportable Segment) (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Segment Reporting Information [Line Items]
Net interest income	$ 220,621	$ 220,464	$ 212,078	$ 206,725	$ 207,796	$ 209,892	$ 209,198	$ 217,702	$ 859,888	$ 844,588	$ 871,634
Provision for loan and lease losses	12,928	11,997	10,657	11,672	13,171	13,091	10,589	4,823	47,254	41,674	36,589
Non-interest income	70,450	75,402	71,119	60,225	98,620	80,710	74,659	45,951	277,196	299,940	275,724
Non-interest expense	192,786	188,354	184,021	182,714	183,468	181,187	188,511	183,989	747,875	737,155	763,642
Income before income taxes	85,357	95,515	88,519	72,564	109,777	96,324	84,757	74,841	341,955	365,699	347,127
Provision for income taxes	3,486	34,182	31,707	26,561	40,502	34,515	30,470	27,272	95,936	132,759	124,588
Net income	81,871	$ 61,333	$ 56,812	$ 46,003	69,275	$ 61,809	$ 54,287	$ 47,569	246,019	232,940	222,539
Total assets	25,741,439				24,813,119				25,741,439	24,813,119	23,406,381
Loans and leases	19,080,184				17,508,663				19,080,184	17,508,663	16,866,536
Total deposits	19,948,300				19,020,985				19,948,300	19,020,985	17,707,189
Commercial Bank
Segment Reporting Information [Line Items]
Net interest income									434,942	422,022	416,385
Provision for loan and lease losses									37,108	35,348	25,655
Non-interest income									52,054	48,227	38,126
Non-interest expense									218,266	203,233	198,614
Income before income taxes									231,622	231,668	230,242
Provision for income taxes									85,700	85,718	85,190
Net income									145,922	145,950	145,052
Total assets	13,856,963				12,829,249				13,856,963	12,829,249	12,342,117
Loans and leases	13,683,264				12,640,383				13,683,264	12,640,383	12,153,712
Total deposits	3,776,080				3,288,837				3,776,080	3,288,837	2,955,578
Wealth Management
Segment Reporting Information [Line Items]
Net interest income									22,103	21,341	17,412
Provision for loan and lease losses									360	587	38
Non-interest income									18,697	19,554	21,152
Non-interest expense									32,123	34,213	37,355
Income before income taxes									8,317	6,095	1,171
Provision for income taxes									3,077	2,255	433
Net income									5,240	3,840	738
Total assets	437,873				437,058				437,873	437,058	366,438
Loans and leases	423,813				415,737				423,813	415,737	346,905
Total deposits	993,559				1,011,454				993,559	1,011,454	813,327
Retail Bank
Segment Reporting Information [Line Items]
Net interest income									282,622	254,043	240,147
Provision for loan and lease losses									7,701	8,049	8,187
Non-interest income									62,366	62,726	62,141
Non-interest expense									288,236	293,307	290,230
Income before income taxes									49,051	15,413	3,871
Provision for income taxes									18,149	5,703	1,432
Net income									30,902	9,710	2,439
Total assets	2,143,830				1,893,433				2,143,830	1,893,433	1,720,569
Loans and leases	2,054,058				1,806,554				2,054,058	1,806,554	1,624,004
Total deposits	12,449,568				12,032,906				12,449,568	12,032,906	11,352,058
Home Lending
Segment Reporting Information [Line Items]
Net interest income									39,487	41,435	35,130
Provision for loan and lease losses									1,692	(3,426)	2,709
Non-interest income									142,763	163,527	144,846
Non-interest expense									146,690	154,922	142,150
Income before income taxes									33,868	53,466	35,117
Provision for income taxes									12,531	19,783	12,994
Net income									21,337	33,683	22,123
Total assets	3,355,189				3,243,600				3,355,189	3,243,600	3,281,256
Loans and leases	2,921,897				2,685,181				2,921,897	2,685,181	2,771,990
Total deposits	222,494				229,358				222,494	229,358	17,374
Corporate & Other
Segment Reporting Information [Line Items]
Net interest income									80,734	105,747	162,560
Provision for loan and lease losses									393	1,116	0
Non-interest income									1,316	5,906	9,459
Non-interest expense									62,560	51,480	95,293
Income before income taxes									19,097	59,057	76,726
Provision for income taxes									(23,521)	19,300	24,539
Net income									42,618	39,757	52,187
Total assets	5,947,584				6,409,779				5,947,584	6,409,779	5,696,001
Loans and leases	(2,848)				(39,192)				(2,848)	(39,192)	(30,075)
Total deposits	$ 2,506,599				$ 2,458,430				$ 2,506,599	$ 2,458,430	$ 2,568,852