v3.2.0.727
Inventories - Additional Information (Detail) - USD ($)
$ in Millions
3 Months Ended 6 Months Ended
Jun. 30, 2015
Jun. 30, 2014
Jun. 30, 2015
Jun. 30, 2014
Inventory Disclosure [Abstract]        
Cost of sales LIFO adjustment $ 1.5 $ 1.9 $ 10.8 $ 6.8