Commitments and Contingencies (Details) $ in Millions	1 Months Ended	3 Months Ended		12 Months Ended
	Oct. 31, 2018 USD ($)	Sep. 30, 2020 USD ($) claim	Mar. 31, 2019	Dec. 31, 2019 USD ($) claim	Dec. 31, 2018 USD ($)	Mar. 31, 2020 lawsuit	Jan. 23, 2020 claim	Aug. 01, 2018 numberOfLawFirms
Commitments and Contingencies Disclosure [Abstract]
Outstanding letters of credit and surety bonds		$ 140
Loss Contingencies [Line Items]
Lawsuits consolidated | lawsuit						3
Number of consolidated class action lawsuits | claim							4
Number of law firms retained | numberOfLawFirms								2
Contributions to grantor trust	$ 120
Costs for settlement and defense of asbestos claims, net of insurance recoveries and taxes				$ 58	$ 45
Asbestos Claims [Member]
Loss Contingencies [Line Items]
Number of pending asbestos claims | claim		31,180		30,950
Number of new asbestos claims | claim		830
Number of asbestos claims closed or moved to inactive docket | claim		840
CBS Television City [Member]
Loss Contingencies [Line Items]
Guaranteed cash flow period			5 years
Estimated liability		$ 100
Famous Players [Member]
Loss Contingencies [Line Items]
Estimated liability		$ 67