Accounting Policies and Supplemental Disclosures - Video and Music Content (Details) - USD ($) $ in Billions	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2020
Accounting Policies [Abstract]
Digital video and music content, capitalized costs	$ 10.1		$ 10.1		$ 6.8
Digital video and music content, expense	$ 3.3	$ 2.8	$ 9.4	$ 8.0