Commitments and Guarantees, Contingent Liabilities and Litigation and Regulatory Matters (Litigation Narrative) (Details) $ in Millions	1 Months Ended						31 Months Ended
	Dec. 31, 2017 USD ($) defendant	Feb. 28, 2017 plaintiff	Jun. 30, 2014 case plaintiff	Feb. 29, 2012 state_and_jurisdiction	Jan. 31, 2012 state_and_jurisdiction	Mar. 31, 2008 state	Dec. 31, 2016 USD ($)	Jan. 31, 2018 plaintiff	Feb. 28, 2015 plaintiff	Jul. 31, 2014 defendant	May 31, 2014 defendant
Loss Contingencies [Line Items]
Estimate of possible losses in excess of accruals (less than) for litigation and regulatory matters | $	$ 250
Unclaimed property against the Social Security Master Death File
Loss Contingencies [Line Items]
Number of states accepting agreement | state_and_jurisdiction				20	20
Wells Fargo MyTerm Sales
Loss Contingencies [Line Items]
Annualized new premiums sales | $							$ 4
Bouder v. Prudential Financial, Inc. And Prudential Insurance Company Of America
Loss Contingencies [Line Items]
Loss Contingency, Alleged Violations Of Overtime And Wage Payment Laws, Number Of States | state						9
Residential mortgage-backed securities | Positive Outcome of Litigation
Loss Contingencies [Line Items]
Number of other institutions filing actions along with Company			9
Number of actions filed by the Company in New York state court | case			6
Number of Trusts represented in legal action filed by the Company (more than)			2,200
Number of defendants in legal action filed by the company | defendant										6
Residential mortgage-backed securities | PICA et al. v. Deutsche Bank, et al.
Loss Contingencies [Line Items]
Loss Contingency, New Claims Filed, Number		62
Loss Contingency, Pending Claims, Number		41
Loss Contingency, Claims Dismissed, Number		21
Residential mortgage-backed securities | PICA et al. v. U.S. Bank N.A.
Loss Contingencies [Line Items]
Number of Trusts represented in legal action filed by the Company (more than)									770
London Interbank Offered Rate (LIBOR) | Positive Outcome of Litigation
Loss Contingencies [Line Items]
Number of defendants in legal action filed by the company | defendant											10
Subsequent Event | Residential mortgage-backed securities | PICA et al. v. U.S. Bank N.A.
Loss Contingencies [Line Items]
Number of Trusts represented in legal action filed by the Company (more than)								77
Pending Litigation
Loss Contingencies [Line Items]
Loss Contingency, Number of Defendants | defendant	19