Consolidated Balance Sheets (Parenthetical) - USD ($) shares in Millions, $ in Millions	Sep. 30, 2016	Sep. 30, 2015
Current assets
Allowance for doubtful accounts, current	$ 14	$ 11
Stockholders' Equity
Common stock, shares authorized	200	200
Common stock, par value per share (usd per share)	$ 0.01	$ 0.01
Common stock, shares, issued	62	67

A valuation allowance for trade and other receivables due to an Entity within one year (or the normal operating cycle, whichever is longer) that are expected to be uncollectible.

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Face amount or stated value per share of common stock.

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The maximum number of common shares permitted to be issued by an entity's charter and bylaws.

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Number of shares of common stock outstanding. Common stock represent the ownership interest in a corporation.

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