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Segments (Schedule Of Financial Information By Segment) (Details) $ in Thousands		12 Months Ended
		Dec. 31, 2020 USD ($) Operating_Segments	Dec. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)
Segment Reporting Information [Line Items]
Number of operating segments | Operating_Segments		3
Net interest income		$ 829,847	$ 821,293	$ 823,825
Provision for loan losses		(137,190)	(50,438)	(42,694)
Non-interest income		505,867	524,703	501,341
Investment securities gains (losses), net	[1]	11,032	3,626	(488)
Non-interest expense		(768,378)	(767,398)	(737,821)
Income before income taxes		441,178	531,786	544,163
Consumer Segment [Member]
Segment Reporting Information [Line Items]
Net interest income		321,040	315,782	294,798
Provision for loan losses		(31,220)	(44,987)	(40,571)
Non-interest income		148,568	135,257	126,253
Investment securities gains (losses), net		0	0	0
Non-interest expense		(297,724)	(297,398)	(286,181)
Income before income taxes		140,664	108,654	94,299
Commercial Segment [Member]
Segment Reporting Information [Line Items]
Net interest income		414,724	343,233	344,972
Provision for loan losses		(3,724)	(4,204)	(1,134)
Non-interest income		194,517	203,952	202,527
Investment securities gains (losses), net		0	0	0
Non-interest expense		(316,074)	(309,163)	(297,847)
Income before income taxes		289,443	233,818	248,518
Wealth Segment [Member]
Segment Reporting Information [Line Items]
Net interest income		57,925	47,863	46,990
Provision for loan losses		12	(174)	32
Non-interest income		188,948	180,836	169,844
Investment securities gains (losses), net		0	0	0
Non-interest expense		(124,964)	(122,784)	(122,247)
Income before income taxes		121,921	105,741	94,619
Segment Totals [Member]
Segment Reporting Information [Line Items]
Net interest income		793,689	706,878	686,760
Provision for loan losses		(34,932)	(49,365)	(41,673)
Non-interest income		532,033	520,045	498,624
Investment securities gains (losses), net		0	0	0
Non-interest expense		(738,762)	(729,345)	(706,275)
Income before income taxes		552,028	448,213	437,436
Other/Elimination [Member]
Segment Reporting Information [Line Items]
Net interest income		36,158	114,415	137,065
Provision for loan losses		(102,258)	(1,073)	(1,021)
Non-interest income		(26,166)	4,658	2,717
Investment securities gains (losses), net		11,032	3,626	(488)
Non-interest expense		(29,616)	(38,053)	(31,546)
Income before income taxes		$ (110,850)	$ 83,573	$ 106,727
[1] Available for sale debt securities, equity securities, and other securities.

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