Subsequent Events (Details) - USD ($) $ in Millions		1 Months Ended
	Nov. 03, 2021	Oct. 31, 2021
Subsequent Events
Percentage of common stock transferred on spin off	80.10%
Number of shares issued per share on spin off	0.2
Subsequent event
Subsequent Events
Percentage of common stock transferred on spin off	80.10%
Maximum amount of receivables which could be sold in factoring arrangement		$ 1,100
Subsequent event | IBM.
Subsequent Events
Net proceeds		963,000
Number of shares issued per share on spin off	0.2
Ownership percentage retained	19.90%
Subsequent event | Fixed Rate, Senior Unsecured Notes
Subsequent Events
Aggregate principal amount		2,400
Subsequent event | Senior Notes due 2026
Subsequent Events
Aggregate principal amount		$ 700
Coupon rate (as a percent)		2.05%
Subsequent event | Senior Notes due 2028
Subsequent Events
Aggregate principal amount		$ 500
Coupon rate (as a percent)		2.70%
Subsequent event | Senior Notes due 2031
Subsequent Events
Aggregate principal amount		$ 650
Coupon rate (as a percent)		3.15%
Subsequent event | Senior Notes due 2041
Subsequent Events
Aggregate principal amount		$ 550
Coupon rate (as a percent)		4.10%
Subsequent event | Variable rate term loan
Subsequent Events
Aggregate principal amount		$ 500
Term of debt		3 years
Subsequent event | Global credit facility
Subsequent Events
Aggregate principal amount		$ 3,200
Term of debt		5 years