Share Repurchases (Narrative) (Details) - Two Thousand And Fifteen Share Repurchase Program [Member] - USD ($) $ in Billions	Apr. 30, 2017	Oct. 13, 2015
Equity, Class of Treasury Stock [Line Items]
Share repurchase program, authorized amount		$ 20.0
Stock repurchase program, remaining authorized repurchase amount	$ 7.0

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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