Goodwill and Other Intangible Assets (Goodwill And Other Intangible Assets) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Goodwill [Roll Forward]
Goodwill, Gross, beginning balance	$ 1,900,727
Goodwill, Impaired, Accumulated Impairment Loss	113,076
Goodwill, Total, beginning balance	1,787,651	$ 1,787,651
Goodwill impairment	1,784,936	0	$ 0
Goodwill, Period Increase (Decrease)	1,784,936	0	0
Goodwill, Gross	(1,900,727)	(1,900,727)
Goodwill, Impaired, Accumulated Impairment Loss	1,898,012	113,076
Goodwill, Total, ending balance	2,715	1,787,651	1,787,651
Finite-Lived Intangible Assets [Line Items]
Goodwill	2,715	1,787,651	1,787,651
Finite-lived Intangible Assets [Roll Forward]
Other Intangible Assets, Gross, Beginning Balance	113,471	113,471	113,471
Other Intangible Assets, Accumulated Amortization, Beginning Balance	(95,125)	(89,507)	(83,341)
Total Expected Amortization, Beginning Balance	18,346	23,964	30,130
Other Intangible Assets, Amortization	(4,986)	(5,618)	(6,166)
Other Intangible Assets, Gross, Ending Balance	113,471	113,471	113,471
Other Intangible Assets, Accumulated Amortization, Ending Balance	(100,111)	(95,125)	(89,507)
Total Expected Amortization, Ending Balance	13,360	18,346	23,964
Wholesale Bank
Goodwill [Roll Forward]
Goodwill, Total, beginning balance	1,033,744	1,033,744
Goodwill impairment	1,033,744
Goodwill, Total, ending balance	0	1,033,744	1,033,744
Finite-Lived Intangible Assets [Line Items]
Goodwill	0	1,033,744	1,033,744
Wealth Management
Goodwill [Roll Forward]
Goodwill, Total, beginning balance	2,715	2,715
Goodwill impairment	0
Goodwill, Total, ending balance	2,715	2,715	2,715
Finite-Lived Intangible Assets [Line Items]
Goodwill	2,715	2,715	2,715
Retail Bank
Goodwill [Roll Forward]
Goodwill, Total, beginning balance	751,192	751,192
Goodwill impairment	751,192
Goodwill, Total, ending balance	0	751,192	751,192
Finite-Lived Intangible Assets [Line Items]
Goodwill	$ 0	$ 751,192	$ 751,192