Summary of significant accounting policies - Additional Information (Detail) $ in Millions	12 Months Ended
	Dec. 31, 2016 USD ($) segment tradename	Dec. 31, 2015 USD ($)
Summary Of Significant Accounting Policies [Line Items]
Number of reporting units | segment	6
Number of reporting units, two-step quantitative impairment test | segment	3
Number of trade names | tradename	3
Weighted average amortization period of intangible assets, in years	15 years
Reserve for estimated rebates | $	$ 11.6	$ 11.1
Minimum | Intellectual property
Summary Of Significant Accounting Policies [Line Items]
Useful life of Intangible assets, in years	3 years
Minimum | Customer Lists
Summary Of Significant Accounting Policies [Line Items]
Useful life of Intangible assets, in years	5 years
Minimum | Distribution rights
Summary Of Significant Accounting Policies [Line Items]
Useful life of Intangible assets, in years	3 years
Minimum | Trade names
Summary Of Significant Accounting Policies [Line Items]
Useful life of Intangible assets, in years	1 year
Maximum | Intellectual property
Summary Of Significant Accounting Policies [Line Items]
Useful life of Intangible assets, in years	20 years
Maximum | Customer Lists
Summary Of Significant Accounting Policies [Line Items]
Useful life of Intangible assets, in years	30 years
Maximum | Distribution rights
Summary Of Significant Accounting Policies [Line Items]
Useful life of Intangible assets, in years	22 years
Maximum | Trade names
Summary Of Significant Accounting Policies [Line Items]
Useful life of Intangible assets, in years	30 years
Building
Summary Of Significant Accounting Policies [Line Items]
Useful life of plant and equipment, in years	30 years
Machinery and Equipment | Minimum
Summary Of Significant Accounting Policies [Line Items]
Useful life of plant and equipment, in years	3 years
Machinery and Equipment | Maximum
Summary Of Significant Accounting Policies [Line Items]
Useful life of plant and equipment, in years	10 years
Computer Equipment and Software | Minimum
Summary Of Significant Accounting Policies [Line Items]
Useful life of plant and equipment, in years	3 years
Computer Equipment and Software | Maximum
Summary Of Significant Accounting Policies [Line Items]
Useful life of plant and equipment, in years	10 years
Allowance for Sales Returns [Member]
Summary Of Significant Accounting Policies [Line Items]
Reserve for returns and allowances | $	$ 4.4	$ 4.9