Share-Based Compensation Plans - Total Compensation Expense for Share-Based Payment Arrangements to Employees (Detail) - USD ($) $ in Millions |
12 Months Ended | ||
---|---|---|---|
Dec. 31, 2020 |
Dec. 31, 2019 |
Dec. 31, 2018 |
|
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | |||
Total Share-Based Compensation Expense | $ 91.4 | $ 107.9 | $ 130.9 |
Tax Benefits Recognized | 22.9 | 26.7 | 32.5 |
Restricted Stock Unit Awards | |||
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | |||
Total Share-Based Compensation Expense | 78.1 | 81.4 | 96.3 |
Stock Options | |||
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | |||
Total Share-Based Compensation Expense | 0.5 | 1.4 | 2.6 |
Performance Stock Units | |||
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | |||
Total Share-Based Compensation Expense | $ 12.8 | $ 25.1 | $ 32.0 |