Goodwill and Other Acquired Intangible Assets Narrative (Details)	12 Months Ended
	Dec. 31, 2015 USD ($) reporting_unit	Dec. 31, 2014 USD ($)	Dec. 31, 2013 USD ($)	Oct. 31, 2015 USD ($)
Acquired Finite-Lived Intangible Assets [Line Items]
Goodwill acquired during the year	$ 13,350,000	$ 89,401,000
Goodwill impairment	$ 17,000,000	12,500,000	$ 0
Number Of Reporting Units With No Goodwill Impairments | reporting_unit	2
Disposition adjustments	$ 0	(1,699,000)
Number of reporting units | reporting_unit	3
Goodwill	$ 5,043,197,000	5,046,847,000	4,971,645,000
Recognized accumulated goodwill impairment losses	4,792,203,000	4,775,203,000	4,762,703,000
Amount of combined fair value of reporting units with goodwill exceeding combined carrying value				$ 719,000,000
Amount of combined fair value of reporting units with goodwill exceeding combined carrying value if discount rate was increased 50 basis points				190,000,000
Amount of combined carrying value of reporting units with goodwill exceeding combined fair value if discount rate was increased 100 basis points				$ 988,000,000
Discount rate, increase to rate used in determining fair value, scenario one				0.50%
Discount rate, increase to rate used in determining fair value, scenario two				1.00%
Amortization of intangibles	$ 39,208,000	50,856,000	$ 60,691,000
Core deposit intangibles
Acquired Finite-Lived Intangible Assets [Line Items]
Estimated useful life	2 years 8 months 12 days
Other identifiable intangibles
Acquired Finite-Lived Intangible Assets [Line Items]
Estimated useful life	2 years 1 month 6 days
Corporate and investment banking
Acquired Finite-Lived Intangible Assets [Line Items]
Goodwill	$ 804,000,000
Recognized accumulated goodwill impairment losses	249,000,000
Simple
Acquired Finite-Lived Intangible Assets [Line Items]
Goodwill impairment	0	$ 12,500,000
Goodwill	60,000,000
Recognized accumulated goodwill impairment losses	30,000,000
Consumer and Commercial Banking
Acquired Finite-Lived Intangible Assets [Line Items]
Goodwill	4,200,000,000
Recognized accumulated goodwill impairment losses	3,800,000,000
Reporting units with no remaining goodwill balance
Acquired Finite-Lived Intangible Assets [Line Items]
Recognized accumulated goodwill impairment losses	694,000,000
Simple | Simple
Acquired Finite-Lived Intangible Assets [Line Items]
Goodwill impairment	$ 17,000,000