Basis of Presentation - Additional Information (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2017	Dec. 31, 2016
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Incremental tax expense	$ 0.3
Percentage inventory valued under LIFO	98.40%	98.30%
Higher inventory if FIFO applied entirely	$ 157.0	$ 147.9
Effect of LIFO inventory liquidation on income	1.6
LIFO expense related to inflation increase in cost of sales	10.7
Increase in cost of sales due to LIFO accounting method	$ 9.1