Acquisitions and Investments - Acquisitions Contributed Aggregate Revenues from Their Respective Acquisition Dates (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Asset Acquisition [Line Items]
Total Contributed Aggregate Revenue	$ 173	$ 120	$ 18
2021 Acquisitions
Asset Acquisition [Line Items]
Total Contributed Aggregate Revenue	19	0	0
2020 Acquisitions
Asset Acquisition [Line Items]
Total Contributed Aggregate Revenue	137	99	0
2019 Acquisitions
Asset Acquisition [Line Items]
Total Contributed Aggregate Revenue	$ 17	$ 21	$ 18