COVER PAGE - shares	6 Months Ended
	Jun. 30, 2019	Aug. 05, 2019
Document Information [Line Items]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Jun. 30, 2019
Document Transition Report	false
Entity File Number	001-09553
Entity Registrant Name	CBS CORPORATION
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	04-2949533
Entity Address, Address Line One	51 W. 52nd Street,
Entity Address, City or Town	New York,
Entity Address, State or Province	NY
Entity Address, Postal Zip Code	10019
City Area Code	212
Local Phone Number	975-4321
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Central Index Key	0000813828
Document Fiscal Period Focus	Q2
Document Fiscal Year Focus	2019
Current Fiscal Year End Date	--12-31
Amendment Flag	false
Common Class A [Member]
Document Information [Line Items]
Title of 12(b) Security	Class A Common Stock, $0.001 par value
Trading Symbol	CBS.A
Security Exchange Name	NYSE
Shares of common stock outstanding		22,803,151
Common Class B [Member]
Document Information [Line Items]
Title of 12(b) Security	Class B Common Stock, $0.001 par value
Trading Symbol	CBS
Security Exchange Name	NYSE
Shares of common stock outstanding		351,863,655