Accounting Policies and Supplemental Disclosures - Unearned Revenue (Details) - USD ($) $ in Billions	3 Months Ended
	Mar. 31, 2022	Dec. 31, 2021
Accounting Policies [Abstract]
Unearned revenue		$ 14.0
Unearned revenue, revenue recognized	$ 5.1
Unearned revenue, long-term	2.5	$ 2.2
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2022-04-01
Accounting Policies [Abstract]
Remaining performance obligation, contracts exceeding one year	$ 88.9
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligation, weighted average remaining life	3 years 9 months 18 days