Description of Business and Basis of Presentation (Narrative) (Details) - USD ($) $ in Millions		3 Months Ended
	Mar. 19, 2019	Sep. 30, 2020	Sep. 30, 2019
Disclosure Basis Of Presentation Details [Line Items]
Settlement of Divestiture Tax prepayment		$ 462	$ 0
Separation And Distribution Agreement
Disclosure Basis Of Presentation Details [Line Items]
Prepayment of the Company's share of the estimated taxes resulting from the anticipated divestitures by Disney of certain assets	$ 700
Settlement of Divestiture Tax prepayment		$ 462