Financial Statement Presentation and Significant Accounting Policies - Additional Information (Detail) - USD ($) $ in Millions	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015	Dec. 31, 2015
Schedule Of Significant Accounting Policies [Line Items]
Property, plant and equipment, net	$ 290.4		$ 290.4		$ 301.5
Deferred income taxes	5.9		5.9		6.7
Net earnings (loss)	(1.2)	$ (10.8)	(11.2)	$ (4.3)
Cost of sales	298.6	347.4	591.4	480.3
Selling, general and administrative expenses	$ 14.6	$ 15.7	$ 30.0	$ 23.3
Immaterial error correction			Management has concluded that the error reflected in the December 31, 2015 consolidated financial statements was not material and that the error correction in 2016 is not expected to be material to the full year results of operations.
Overstatement Due To Depreciation Expense Error [Member]
Schedule Of Significant Accounting Policies [Line Items]
Property, plant and equipment, net					3.8
Deferred income taxes					1.1
Net earnings (loss)					$ 2.7
Adjustment To Correct Depreciation Expense Error [Member]
Schedule Of Significant Accounting Policies [Line Items]
Cost of sales			$ 3.7
Selling, general and administrative expenses			$ 0.1