Financial Statement Presentation and Significant Accounting Policies - Additional Information (Detail)	3 Months Ended
	Mar. 31, 2017 USD ($) Entity	Mar. 31, 2016 USD ($)	Dec. 31, 2016 USD ($)
Schedule Of Significant Accounting Policies [Line Items]
Inventory estimated net realizable value	$ 111,800,000		$ 118,200,000
Intellectual property estimated net realizable value	11,900,000		12,500,000
Cost of sales	323,700,000	$ 292,800,000
Selling, general and administrative expenses	$ 14,400,000	15,400,000
Immaterial error correction	Management concluded that the error correction in 2016 was not material to the full year results of operations.
Number of VIE treated as unconsolidated equity method investment | Entity	1
Equity method investment	$ 6,100,000		$ 5,000,000
Net excess tax benefits from share-based compensation awards	0
Payments made for employee payroll tax withholding liabilities associated with share-based compensation awards	0	0
Beck Aluminum International, LLC (“Beck Trading”)
Schedule Of Significant Accounting Policies [Line Items]
Equity method investment	6,100,000
Maximum loss exposure amount	9,400,000
Adjustment To Correct Depreciation Expense Error
Schedule Of Significant Accounting Policies [Line Items]
Cost of sales		3,700,000
Selling, general and administrative expenses		$ 100,000
Cosmedicine | Disposal Group, Held-for-sale or Disposed of by Sale, Not Discontinued Operations
Schedule Of Significant Accounting Policies [Line Items]
Inventory estimated net realizable value	0
Cosmedicine | Disposal Group, Held-for-sale or Disposed of by Sale, Not Discontinued Operations | Intellectual Property
Schedule Of Significant Accounting Policies [Line Items]
Intellectual property estimated net realizable value	$ 0