Supplemental Financial Information (Narrative) (Details) $ in Millions		3 Months Ended
	Jan. 31, 2019	Jun. 30, 2020 USD ($) title	Mar. 31, 2020 USD ($)	Mar. 31, 2019 USD ($)	Dec. 31, 2019 USD ($)
Variable Interest Entities
Assets			$ 49,045		$ 49,519
Gain on Sale of Assets
Sale of property and sound stage			146	$ 741
Gain on sale of assets			0	549
Lease Income
Lease income			34	40
CBS Television City [Member]
Gain on Sale of Assets
Sale of property and sound stage				$ 750
Guaranteed cash flow period	5 years			5 years
Gain on sale of property and sound stage operation, net				$ 386
Miramax [Member] | Forecast [Member]
Pending Acquisition of Miramax
Percentage of interest acquired		49.00%
Consideration transferred		$ 375
Upfront cash payment		150
Commitment to invest, annual amount		45
Commitment to invest over next five years		$ 225
Titles added to existing library | title		700
Variable Interest Entity, Primary Beneficiary [Member]
Variable Interest Entities
Assets			137		141
Liabilities			$ 32		$ 22