Goodwill (Schedule of Goodwill) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2019
Goodwill [Roll Forward]
Goodwill, Gross, Beginning Balance			$ 1,900,727
Goodwill, Impaired, Accumulated Impairment Loss	$ (1,898,012)		(1,898,012)
Goodwill, Beginning Balance			1,787,651
Goodwill impairment	0	$ 0	(1,784,936)	$ 0
Goodwill, Period Increase (Decrease)			(1,784,936)
Goodwill, Gross, Ending Balance	1,900,727		1,900,727
Goodwill, Impaired, Accumulated Impairment Loss, Ending Balance	1,898,012		1,898,012		$ 113,076
Goodwill, Ending Balance	2,715		2,715
Wholesale Bank
Goodwill [Roll Forward]
Goodwill, Beginning Balance			1,033,744
Goodwill impairment			(1,033,744)
Goodwill, Ending Balance	0		0
Wealth Management
Goodwill [Roll Forward]
Goodwill, Beginning Balance			2,715
Goodwill impairment			0
Goodwill, Ending Balance	2,715		2,715
Retail Bank
Goodwill [Roll Forward]
Goodwill, Beginning Balance			751,192
Goodwill impairment			(751,192)
Goodwill, Ending Balance	$ 0		$ 0