Share Repurchases (Narrative) (Details) - 2013 Share repurchase program - USD ($) $ in Billions	Jul. 31, 2015	Jun. 06, 2013
Equity, Class of Treasury Stock [Line Items]
Share repurchase program, authorized amount		$ 15.0
Stock repurchase program, remaining authorized repurchase amount	$ 9.0

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.

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