Accounting Policies and Supplemental Disclosures - Video and Music Content (Details) - USD ($) $ in Billions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2019
Accounting Policies [Abstract]
Digital video and music content, capitalized costs	$ 6.3		$ 6.3		$ 5.8
Digital video and music content, expense	$ 2.8	$ 1.9	$ 8.0	$ 5.5