Segments (Schedule Of Financial Information By Segment) (Details)	3 Months Ended		9 Months Ended
	Sep. 30, 2016 USD ($)	Sep. 30, 2015 USD ($)	Sep. 30, 2016 USD ($)		Sep. 30, 2015 USD ($)
Segment Reporting Information [Line Items]
Segment Reporting Information, Intersegment Revenue	$ 0	$ 0	$ 0		$ 0
Number of operating segments			3		3
Net interest income	171,243,000	162,038,000	$ 506,847,000		$ 471,833,000
Provision for loan losses	(7,263,000)	(8,364,000)	(25,918,000)		(19,541,000)
Non-interest income	119,319,000	111,288,000	354,913,000		332,097,000
Investment securities gains (losses), net	(1,965,000)	(378,000)	(3,704,000)	[1]	7,800,000	[1]
Non-interest expense	(181,242,000)	(171,402,000)	(535,804,000)		(500,710,000)
Income before income taxes	100,092,000	93,182,000	296,334,000		291,479,000
Consumer Segment [Member]
Segment Reporting Information [Line Items]
Net interest income	67,375,000	67,085,000	201,166,000		199,265,000
Provision for loan losses	(9,033,000)	(8,605,000)	(26,533,000)		(25,500,000)
Non-interest income	34,229,000	31,099,000	97,165,000		87,462,000
Investment securities gains (losses), net	0	0	0		0
Non-interest expense	(70,113,000)	(69,158,000)	(209,649,000)		(203,440,000)
Income before income taxes	22,458,000	20,421,000	62,149,000		57,787,000
Commercial Segment [Member]
Segment Reporting Information [Line Items]
Net interest income	78,537,000	74,476,000	231,552,000		218,699,000
Provision for loan losses	2,432,000	166,000	3,919,000		842,000
Non-interest income	49,832,000	47,486,000	149,240,000		144,685,000
Investment securities gains (losses), net	0	0	0		0
Non-interest expense	(71,425,000)	(68,713,000)	(211,961,000)		(199,097,000)
Income before income taxes	59,376,000	53,415,000	172,750,000		165,129,000
Wealth Segment [Member]
Segment Reporting Information [Line Items]
Net interest income	10,782,000	10,427,000	32,604,000		31,921,000
Provision for loan losses	(5,000)	106,000	(120,000)		114,000
Non-interest income	36,675,000	33,980,000	107,696,000		102,517,000
Investment securities gains (losses), net	0	0	0		0
Non-interest expense	(28,185,000)	(27,182,000)	(85,025,000)		(81,432,000)
Income before income taxes	19,267,000	17,331,000	55,155,000		53,120,000
Segment Totals [Member]
Segment Reporting Information [Line Items]
Net interest income	156,694,000	151,988,000	465,322,000		449,885,000
Provision for loan losses	(6,606,000)	(8,333,000)	(22,734,000)		(24,544,000)
Non-interest income	120,736,000	112,565,000	354,101,000		334,664,000
Investment securities gains (losses), net	0	0	0		0
Non-interest expense	(169,723,000)	(165,053,000)	(506,635,000)		(483,969,000)
Income before income taxes	101,101,000	91,167,000	290,054,000		276,036,000
Other Elimination [Member]
Segment Reporting Information [Line Items]
Net interest income	14,549,000	10,050,000	41,525,000		21,948,000
Provision for loan losses	(657,000)	(31,000)	(3,184,000)		5,003,000
Non-interest income	(1,417,000)	(1,277,000)	812,000		(2,567,000)
Investment securities gains (losses), net	(1,965,000)	(378,000)	(3,704,000)		7,800,000
Non-interest expense	(11,519,000)	(6,349,000)	(29,169,000)		(16,741,000)
Income before income taxes	$ (1,009,000)	$ 2,015,000	$ 6,280,000		$ 15,443,000

[1] Available for sale and non-marketable securities