Shareholders' Equity (Details) - USD ($) $ in Millions	4 Months Ended	8 Months Ended	12 Months Ended
	Apr. 30, 2021	Dec. 31, 2021	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019	May 31, 2021	Jun. 30, 2018
Stockholders' Equity Note [Abstract]
Purchase for treasury	$ 1,000.0	$ 250.0	$ 1,250.0	$ 500.0	$ 4,400.0
Stock repurchase program, authorized amount						$ 5,000.0	$ 8,000.0
Remaining authorized repurchase amount		$ 4,750.0	$ 4,750.0
Preferred stock, shares authorized (in shares)		5,000,000	5,000,000
Shares issued (in shares)		0	0	0
Shares held in employee trust (in shares)		50,000,000	50,000,000	50,000,000
Employee benefit trust		$ 3,013.2	$ 3,013.2	$ 3,013.2