Stock Compensation Plans (Details) - USD ($) $ in Millions	3 Months Ended
Mar. 31, 2022	Mar. 31, 2021
Stock Compensation Plans:
Stock compensation expense	$ 147.0	$ 134.0
Stock options
Stock Compensation Plans:
Stock options granted in period (shares)	1,372,400	1,225,000
Award vesting period	3 years
Award expiration period	10 years
Unrecognized compensation cost	$ 380.0
Remaining period over which to recognize unrecognized compensation expense	2 years
Restricted stock
Stock Compensation Plans:
Award vesting period	1 year
Unrecognized compensation cost	$ 0.2
Remaining period over which to recognize unrecognized compensation expense	1 month
Restricted stock units
Stock Compensation Plans:
Awards other than stock options granted in period (shares)	423,600	345,100
Award vesting period	3 years
Unrecognized compensation cost	$ 378.0
Remaining period over which to recognize unrecognized compensation expense	2 years

Amount of expense for award under share-based payment arrangement. Excludes amount capitalized.

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Weighted-average period over which cost not yet recognized is expected to be recognized for award under share-based payment arrangement, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.

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The number of grants made during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan).

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