Related Parties (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011	Dec. 31, 2011
National Amusements Inc. [Member]
Related Party Transaction [Line Items]
NAI ownership of CBS Corp. Class A Common Stock (percentage)	79.00%
NAI ownership of CBS Corp. Class A and Class B Common Stock on a combined basis (percentage)	6.00%
Viacom Inc. [Member]
Related Party Transaction [Line Items]
Revenues from transactions with related party	$ 64	$ 51
Expenses from transactions with related party	6	6
Receivables from Viacom Inc., current	105		102
Other assets (Receivables, noncurrent) from Viacom Inc.	179		198
Total amounts due from Viacom Inc.	284		300
Accounts payable to Viacom Inc.	1		3
Program rights obligations due to Viacom Inc.	2		2
Total amounts due to Viacom Inc.	3		5
Domestic and International Television Joint Ventures [Member]
Related Party Transaction [Line Items]
Revenues from transactions with related party	$ 36	$ 33