Supplemental Disclosures (Supplemental Operating and Financing Cash Flow Items) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Operating:
Contingent consideration payments	$ (49)	$ (48)	$ (41)
Prior year dispositions cash received	19	0	0
Acquisition/disposition related net charges for adjustments	57	26	68
Adjustments and payments related to contingent consideration	27	(22)	27
Financing:
Contingent purchase consideration	(28)	(54)	(22)
Deferred purchase consideration related to prior years' acquisitions	(89)	(68)	(43)
Payments of deferred and contingent consideration for acquisitions	(117)	(122)	(65)
Receipt of contingent consideration related to prior year dispositions	$ 71	$ 0	$ 0