Segment Information - Summary of Results of Segment Operations (Parenthetical) (Detail) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Revenue from External Customer [Line Items]
Impairment charges	$ 35.1	$ 3.5	$ 14.7	$ 4.7
Gain (loss) on sale of business		2.1	3.2	0.0
Charges related to restructuring activities		2.7	23.4
Goodwill impairment charge	67.2	0.0	67.2	0.0
United States [Member]
Revenue from External Customer [Line Items]
Asset retirement obligation and other restructuring costs		6.9
Wood Treating Facility [Member] | United States [Member]
Revenue from External Customer [Line Items]
Impairment charges			1.9
North American Utility Pole Business [Member]
Revenue from External Customer [Line Items]
Gain (loss) on sale of business			3.2
North American Utility Pole Business [Member] | Wood Treating Facility [Member] | United States [Member]
Revenue from External Customer [Line Items]
Charges related to restructuring activities			5.7
Carbon Materials and Chemicals [Member]
Revenue from External Customer [Line Items]
Impairment charges		3.5	12.8	4.7
Plant closure cost		$ 13.2	36.5	$ 18.1
Goodwill impairment charge	$ 67.2		$ 67.2