New Accounting Standards (Narrative) (Details) $ in Billions	12 Months Ended
Dec. 31, 2016 USD ($)
Accounting Standards Update 2014-09 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Other fee income and other revenue within the scope of ASU 2014-09	$ 1

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

No definition available.

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Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration