Related Parties (Details) - USD ($) $ in Millions	3 Months Ended
Mar. 31, 2017	Mar. 31, 2016	Dec. 31, 2016
Related Party Transaction [Line Items]
SMR Trust ownership in NAI	80.00%
National Amusements, Inc. [Member]
Related Party Transaction [Line Items]
NAI ownership of CBS Corp. Class A Common Stock (percentage)	79.50%
NAI ownership of CBS Corp. Class A and Class B Common Stock on a combined basis (percentage)	9.60%
Viacom Inc. [Member]
Related Party Transaction [Line Items]
Revenues from transactions with related parties	$ 54	$ 36
Expenses from transactions with related parties	5	7
Receivables from Viacom Inc., current	89		$ 113
Receivables from Viacom Inc., noncurrent	60		35
Total amounts due from related parties	149		148
Domestic and International Television Joint Ventures [Member]
Related Party Transaction [Line Items]
Revenues from transactions with related parties	26	$ 32
Total amounts due from related parties	$ 34		$ 47

Chairman Emeritus trust ownership percentage in controlling stockholder

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Percent of CBS Corp. Class A and Class B Common Stock, on a combined basis, owned by NAI as of the financial statement date

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Percent of CBS Corp. Class A Common Stock owned by NAI as of the financial statement date

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For an unclassified balance sheet, amounts due from related parties including affiliates, employees, joint ventures, officers and stockholders, immediate families thereof, and pension funds.

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The aggregate amount of receivables to be collected from related parties where one party can exercise control or significant influence over another party; including affiliates, owners or officers and their immediate families, pension trusts, and so forth, at the financial statement date. which are usually due within one year (or one business cycle).

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Aggregate amount of receivables to be collected from related parties where one party can exercise control or significant influence over another party; including affiliates, owners or officers and their immediate families, pension trusts, and so forth, at the financial statement date. which are usually due after one year (or one business cycle).

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Expenses recognized resulting from transactions (excluding transactions that are eliminated in consolidated or combined financial statements) with related party.

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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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Amount of revenue, fees and commissions earned from transactions between (a) a parent company and its subsidiaries; (b) subsidiaries of a common parent; (c) an entity and trusts for the benefit of employees, for example, but not limited to, pension and profit-sharing trusts that are managed by or under the trusteeship of the entity's management; (d) an entity and its principal, owners, management, or members of their immediate families; and (e) affiliates.

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