Supplemental Disclosures (Supplemental Operating and Financing Cash Flow Items) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Operating:
Contingent consideration payments	$ 0	$ (1)
Acquisition/disposition related net charges for adjustments	10	0
Adjustments and payments related to contingent consideration	10	(1)
Financing:
Contingent purchase consideration	(4)	(10)
Deferred purchase consideration related to prior years' acquisitions	(12)	(27)
Payments of deferred and contingent consideration for acquisitions	(16)	(37)
Receipt of contingent consideration related to prior year dispositions	$ 3	$ 5