Commitments and Contingencies (Narrative) (Details) - USD ($) $ in Millions	1 Months Ended	12 Months Ended
	Jan. 31, 2022	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Loss Contingencies [Line Items]
Operating Lease, Cost		$ 1,200	$ 1,100	$ 1,000
Operating Lease, Payments		$ 921	$ 865	$ 746
Operating Lease, Weighted Average Remaining Lease Term		8 years 8 months 12 days
Operating Lease, Weighted Average Discount Rate, Percent		2.90%
Undrawn Letters Of Credit		$ 181
Surety Bonds Outstanding		$ 1,300
Other Commitments, Description		In 2021, we entered into agreements to acquire multiple companies in the health care sector, most notably, Change Healthcare (NASDAQ: CHNG), subject to regulatory approval and other customary closing conditions.
Subsequent Event
Loss Contingencies [Line Items]
Other Commitment	$ 12,000
Subsequent Event, Description	Additionally, in January 2022, we entered into agreements to acquire multiple companies in the health care sector, subject to regulatory approval and other customary closing conditions.