Carrying value of business after noncash impairment charge.

No definition available.

Name:	cbs_CarryingValueAfterImpairment
Namespace Prefix:	cbs_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Goodwill And Intangible Asset Impairment Net Of Tax

+ References

No definition available.

+ Details

Name:	cbs_GoodwillAndIntangibleAssetImpairmentNetOfTax
Namespace Prefix:	cbs_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- References

No definition available.

+ Details

Name:	cbs_ImpairmentTestingAssumptionsLineItems
Namespace Prefix:	cbs_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Indicated fair value of business based on stock price of the company it intends to merge with.

+ References

No definition available.

+ Details

Name:	cbs_IndicatedFairValueBasedOnStockPrice
Namespace Prefix:	cbs_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Intangible Asset Impairment Net Of Tax

+ References

No definition available.

+ Details

Name:	cbs_IntangibleAssetImpairmentNetOfTax
Namespace Prefix:	cbs_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

NumberOfRadioMarketsImpairment

+ References

No definition available.

+ Details

Name:	cbs_NumberOfRadioMarketsImpairment
Namespace Prefix:	cbs_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

- Definition

Number of radio or television stations received in swap

+ References

No definition available.

+ Details

Name:	cbs_NumberOfStationsReceivedInSwap
Namespace Prefix:	cbs_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

- Definition

Number of relevision or radio stations swapped

+ References

No definition available.

+ Details

Name:	cbs_NumberOfStationsSwapped
Namespace Prefix:	cbs_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

- Definition

Description of the sensitivity of the fair value measurements to changes in unobservable inputs and the inter-relationships between those inputs as well as how those inter-relationships might magnify or mitigate the effect of changes in the unobservable inputs on the fair value measurements.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (g)
-URI http://asc.fasb.org/extlink&oid=66048111&loc=d3e19207-110258

+ Details

Name:	us-gaap_FairValueMeasurementsSensitivityAnalysisDescription
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount of loss from the write-down of an asset representing the future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 20
-Section 50
-Paragraph 2
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=35741047&loc=d3e13854-109267

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 20
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=6388280&loc=d3e13777-109266

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 28
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=66902209&loc=d3e3602-108585

Reference 4: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (e)
-URI http://asc.fasb.org/extlink&oid=35741047&loc=d3e13816-109267

+ Details

Name:	us-gaap_GoodwillImpairmentLoss
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Amount after tax of loss recognized that results from the write-down of an asset representing the future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

+ References

No definition available.

+ Details

Name:	us-gaap_GoodwillImpairmentLossNetOfTax
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Amount of impairment loss resulting from write-down of assets, excluding financial assets and goodwill, lacking physical substance and having a projected indefinite period of benefit to fair value.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 30
-Section 50
-Paragraph 3
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=66006027&loc=d3e16373-109275

+ Details

Name:	us-gaap_ImpairmentOfIntangibleAssetsIndefinitelivedExcludingGoodwill
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Details

Name:	cbs_MarketLocationAxis=cbs_TampaAndCharlotteMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	cbs_MarketLocationAxis=cbs_PhiladelphiaMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	cbs_MarketLocationAxis=cbs_MiamiMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis=cbs_CBSRadioMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DisposalGroupClassificationAxis=us-gaap_DiscontinuedOperationsHeldforsaleMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Discontinued Operations Impairment Test (Details) $ in Millions	12 Months Ended
	Dec. 31, 2016 USD ($) market	Dec. 31, 2015 USD ($) market	Dec. 31, 2014 USD ($) Stations
Impairment Testing Assumptions [Line Items]
Number of radio markets impairment \| market	11	18
Tampa and Charlotte [Member]
Impairment Testing Assumptions [Line Items]
Number of radio stations swapped \| Stations			13
Philadelphia [Member]
Impairment Testing Assumptions [Line Items]
Number of radio stations swapped \| Stations			1
Number of radio stations received in swap \| Stations			2
Miami [Member]
Impairment Testing Assumptions [Line Items]
Number of radio stations received in swap \| Stations			3
CBS Radio [Member] \| Held for Sale [Member]
Impairment Testing Assumptions [Line Items]
FCC licenses impairment, net of tax	$ 22	$ 297
Goodwill, impairment loss, net of tax	405		$ 74
Noncash impairment charge to reduce carrying value of goodwill	408
Noncash impairment charge to reduce carrying value of FCC licenses	36
Goodwill and FCC licenses impairment, net of tax	427
Carrying value of CBS Radio after impairment	1,900
Indicated fair value based on Entercom stock price on day transaction was announced	$ 1,700
Sensitivity analysis of change in Entercom's stock price, impact on fair value of CBS Radio	A 10% increase or decrease in the stock price would result in a change in the fair value of approximately $175 million