Deferred Revenues (Details) - USD ($) $ in Billions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Revenue from Contract with Customer [Abstract]
Deferred revenues	$ 1.7	$ 1.4
Revenue recognized included in beginning deferred revenue	$ 1.3	$ 1.5	$ 1.7