Segment Information (Summary Of Financial Information By Reportable Segment) (Details) - USD ($) $ in Thousands	3 Months Ended		12 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2017
Segment Reporting Information [Line Items]
Net interest income	$ 223,231	$ 206,725
Provision for loan and lease losses	13,656	11,672
Non-interest income	78,567	60,225
Non-interest expense	186,113	182,714
Income before provision for income taxes	102,029	72,564
Provision for income taxes	24,360	26,561
Net income	77,669	46,003	$ 246,019
Total assets	25,875,643		25,741,439
Loans and leases	19,314,589	17,829,638	19,080,184
Total deposits	20,106,856		19,948,300
Commercial Bank
Segment Reporting Information [Line Items]
Net interest income	111,735	102,497
Provision for loan and lease losses	13,368	9,109
Non-interest income	15,729	12,474
Non-interest expense	54,574	49,857
Income before provision for income taxes	59,522	56,005
Provision for income taxes	14,880	20,722
Net income	44,642	35,283
Total assets	14,066,932		13,856,963
Loans and leases	13,896,561		13,683,264
Total deposits	3,747,374		3,776,080
Wealth Management
Segment Reporting Information [Line Items]
Net interest income	6,003	4,429
Provision for loan and lease losses	167	200
Non-interest income	4,896	4,748
Non-interest expense	8,768	8,369
Income before provision for income taxes	1,964	608
Provision for income taxes	491	225
Net income	1,473	383
Total assets	465,097		437,873
Loans and leases	452,537		423,813
Total deposits	998,332		993,559
Retail Bank [Member]
Segment Reporting Information [Line Items]
Net interest income	79,852	68,044
Provision for loan and lease losses	361	1,816
Non-interest income	15,193	14,831
Non-interest expense	71,143	73,670
Income before provision for income taxes	23,541	7,389
Provision for income taxes	5,885	2,734
Net income	17,656	4,655
Total assets	2,075,472		2,143,830
Loans and leases	1,991,976		2,054,058
Total deposits	12,807,253		12,449,568
Home Lending
Segment Reporting Information [Line Items]
Net interest income	8,845	9,498
Provision for loan and lease losses	492	27
Non-interest income	38,408	26,880
Non-interest expense	32,297	40,986
Income before provision for income taxes	14,464	(4,635)
Provision for income taxes	3,616	(1,715)
Net income	10,848	(2,920)
Total assets	3,487,936		3,355,189
Loans and leases	3,001,719		2,921,897
Total deposits	277,678		222,494
Corporate & Other
Segment Reporting Information [Line Items]
Net interest income	16,796	22,257
Provision for loan and lease losses	(732)	520
Non-interest income	4,341	1,292
Non-interest expense	19,331	9,832
Income before provision for income taxes	2,538	13,197
Provision for income taxes	(512)	4,595
Net income	3,050	$ 8,602
Total assets	5,780,206		5,947,584
Loans and leases	(28,204)		(2,848)
Total deposits	$ 2,276,219		$ 2,506,599