Summary of Significant Accounting Policies (Policies)	9 Months Ended
Jun. 30, 2011
Summary Of Significant Accounting Policies [Abstract]
Uses of Estimates	Use of Estimates Preparing financial statements in conformity with GAAP requires management to make estimates, judgments and assumptions that affect the reported amounts of assets and liabilities as of the dates presented and the reported amounts of revenues and expenses during the reporting periods presented. Significant estimates inherent in the preparation of the accompanying Consolidated Financial Statements include estimates of film ultimate revenues, product returns, allowances for doubtful accounts, potential outcome of uncertain tax positions, fair value of acquired assets and liabilities, fair value of equity-based compensation and pension benefit assumptions. Estimates are based on past experience and other considerations reasonable under the circumstances. Actual results may differ from these estimates.
Earnings Per Share	Earnings Per Share Basic earnings per common share excludes potentially dilutive securities and is computed by dividing Net earnings attributable to Viacom by the weighted average number of common shares outstanding during the period. The determination of diluted earnings per common share includes the potential dilutive effect of equity-based compensation awards based upon the application of the treasury stock method. Anti-dilutive common shares are excluded from the calculation of diluted earnings per common share.
Fair Value Measurements	Fair Value of Financial Instruments At June 30, 2011, the Company’s financial assets and liabilities reflected in the Consolidated Financial Statements at fair value consist of marketable securities and derivatives. Fair value for marketable securities is determined utilizing a market approach based on quoted market prices in active markets at period end. Fair value for derivatives is determined utilizing a market-based approach.

Discloses the methodology and assumptions used to compute basic and diluted earnings (loss) per share for each class of common stock and participating security. Addresses all significant policy factors, including any antidilutive items that have been excluded from the computation and takes into account stock dividends, splits and reverse splits that occur after the balance sheet date of the latest reporting period but before the issuance of the financial statements.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 128
-Paragraph 40
-Subparagraph a

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 128
-Paragraph 6, 8-16, 60

Name:	us-gaap_EarningsPerSharePolicyTextBlock
Namespace Prefix:	us-gaap
Data Type:	us-types:textBlockItemType
Balance Type:	na
Period Type:	duration