Legal Actions (Details) $ in Millions				1 Months Ended				3 Months Ended	180 Months Ended
	Mar. 15, 2019	Nov. 30, 2016 USD ($)	Jul. 13, 2012 USD ($)	Dec. 31, 2018 USD ($)	Nov. 30, 2018 USD ($)	Oct. 31, 2018 USD ($)	Aug. 31, 2018 USD ($)	Mar. 31, 2019 USD ($) legal_action	Apr. 20, 2017 USD ($)	Nov. 01, 2018 USD ($)	Oct. 24, 2018 USD ($)	Apr. 20, 2018 USD ($)	Jul. 31, 2017	Nov. 17, 2016 legal_action	May 31, 2016	Dec. 31, 2015 legal_action
ATM Access Fee Litigation [Member]
Legal Actions (Textual) [Abstract]
Loss Contingency, Pending Claims, Number | legal_action														3
Automobile Lending Practices [Member]
Legal Actions (Textual) [Abstract]
Loss Contingency, Pending Claims, Number | legal_action								1
Loss Contingency Accrual, Provision								$ 415.0
Loss Contingency, Estimate of Possible Loss								415.0
Automobile Lending Practices [Member] | All Class Members [Member]
Legal Actions (Textual) [Abstract]
Litigation Settlement, Additional Funding								$ 1.0
Retail Sales Practices, CPI and GAP, and Mortgage interest rate lock matters [Member]
Legal Actions (Textual) [Abstract]
Payments for Legal Settlements				$ 575.0
Civil Money Penalty												$ 1,000.0
Interchange Litigation [Member]
Loss Contingencies [Line Items]
Litigation Settlement, Percentage Of Default Interchange Distributed To Class Merchants			0.10%
Legal Actions (Textual) [Abstract]
Loss Contingency, Estimate of Possible Loss			$ 6,600.0
Litigation Settlement, Default Interchange Distributed To Class Merchants, Distribution Period			8 months
Litigation Settlement, Expense		$ 6,200.0
Litigation Settlement, Funds Remaining from 2012		5,300.0
Litigation Settlement, Additional Funding		900.0
Litigation Settlement, Additional Funding Allocated to WFC		$ 94.5
Mortgage Bankruptcy Loan Modification Litigation [Member]
Legal Actions (Textual) [Abstract]
Loss Contingency, Estimate of Possible Loss											$ 13.5
Approval Date Of The Settlement	Mar. 15, 2019
Mortgage Interest Rate Lock [Member]
Legal Actions (Textual) [Abstract]
Loss Contingency, Pending Claims, Number | legal_action								2
Mortgage Related Regulatory Investigations [Member]
Legal Actions (Textual) [Abstract]
Payments for Legal Settlements					$ 17.0		$ 2,090.0
RMBS Trustee Litigation [Member]
Legal Actions (Textual) [Abstract]
Loss Contingency, Pending Claims, Number | legal_action																4
Loss Contingency, Estimate of Possible Loss										$ 43.0
Sales Practice Matters [Member]
Legal Actions (Textual) [Abstract]
Amounts To Be Paid In Connection With Legal Or Regulatory Matters									$ 142.0
Payments for Legal Settlements						$ 65.0
Gain Contingency, Estimate of Possible Insurance Carriers Payments								$ 240.0
Unauthorized accounts identified									3,500,000
Sales Practice Matters [Member] | All Class Members [Member]
Legal Actions (Textual) [Abstract]
Amounts To Be Paid In Connection With Legal Or Regulatory Matters									$ 25.0
Payments for Legal Settlements				$ 480.0
RMBS Trustee Punitive Class Action Complaint [Member]
Legal Actions (Textual) [Abstract]
RMBS trusts at issue in the State Court Action															261
RMBS Trustee Litigation Civil Complaint [Member]
Legal Actions (Textual) [Abstract]
RMBS trusts at issue in the State Court Action													11
Liability for Contingent Litigation Losses [Member]
Legal Actions (Textual) [Abstract]
Range of possible loss, portion not accrued								$ 3,100.0