XML 145 R86.htm IDEA: XBRL DOCUMENT v3.19.3.a.u2
Stock-Based Compensation - Pre-Tax Stock-Based Compensation Expense from Continuing Operations (Detail) - USD ($)
$ in Millions
12 Months Ended
Dec. 31, 2019
Dec. 31, 2018
Dec. 31, 2017
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]      
Stock-based compensation $ 31.8 $ 37.2 $ 43.6
Tax benefit 6.0 6.2 15.2
Total after tax expense 25.8 31.0 28.4
Stock Option Awards      
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]      
Stock-based compensation 7.0 8.6 7.4
Restricted Stock Units      
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]      
Stock-based compensation 19.4 21.3 21.6
Performance Awards      
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]      
Stock-based compensation 4.2 6.3 13.6
Director Awards      
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]      
Stock-based compensation $ 1.2 $ 1.0 $ 1.0