Quarterly report pursuant to Section 13 or 15(d)

Subsequent Events - Additional Information (Detail)

v3.10.0.1
Subsequent Events - Additional Information (Detail) - USD ($)
$ in Millions
9 Months Ended 12 Months Ended
Oct. 30, 2018
Sep. 30, 2018
Dec. 31, 2016
Feb. 21, 2017
Subsequent Event [Line Items]        
Share repurchase program authorized amount   $ 1,500.0   $ 1,500.0
Share repurchase program expiration date   Feb. 21, 2020 Jun. 30, 2017  
Share repurchase program, remaining authorized capacity   $ 113.3 $ 233.0  
Subsequent Events [Member]        
Subsequent Event [Line Items]        
Share repurchase program authorized amount $ 1,500.0      
Share repurchase program expiration date Oct. 30, 2023