v3.10.0.1
Inventories - Narrative (Detail) - USD ($)
$ in Millions
3 Months Ended 6 Months Ended
Jun. 30, 2018
Jun. 30, 2017
Jun. 30, 2018
Jun. 30, 2017
Inventory Disclosure [Abstract]        
Cost of sales LIFO adjustment $ 1.7 $ (0.4) $ 3.7 $ 4.0