Commitments, Contingent Liabilities and Litigation and Regulatory Matters (Narrative) (Details) $ in Millions	1 Months Ended		31 Months Ended
	Feb. 29, 2012 state	Jan. 31, 2012 state	Dec. 31, 2016 USD ($)	Dec. 31, 2015 USD ($)
Commitments Guarantees Contingent Liabilities And Litigation [Line Items]
Wells Fargo Annualized New Business Premiums			$ 4
Number Of States Needed For Agreement To Become Effective | state	20	20
Purchase Obligation Commercial Mortgage Loan			49	$ 62
Purchase Obligation To Purchase Or Fund Investments			133	$ 131
Maximum
Commitments Guarantees Contingent Liabilities And Litigation [Line Items]
Loss Contingency, Range of Possible Loss, Maximum (less than)			$ 30