Summary of significant accounting policies - Additional Information (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Summary Of Significant Accounting Policies [Line Items]
Weighted average amortization period of intangible assets, in years	16 years
Reserve for returns and allowances	$ 4.2	$ 0.0
Reserve for estimated rebates	18.1	$ 12.2
Intellectual property
Summary Of Significant Accounting Policies [Line Items]
Finite-lived intangible assets	16.9
Finite-lived intangible assets, net of tax	$ 8.6
Minimum | Intellectual property
Summary Of Significant Accounting Policies [Line Items]
Useful life of Intangible assets, in years	5 years
Minimum | Customer relationships
Summary Of Significant Accounting Policies [Line Items]
Useful life of Intangible assets, in years	8 years
Minimum | Distribution rights
Summary Of Significant Accounting Policies [Line Items]
Useful life of Intangible assets, in years	10 years
Minimum | Trade names
Summary Of Significant Accounting Policies [Line Items]
Useful life of Intangible assets, in years	5 years
Minimum | Non-complete agreement
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 relationships
Summary Of Significant Accounting Policies [Line Items]
Useful life of Intangible assets, in years	27 years
Maximum | Distribution rights
Summary Of Significant Accounting Policies [Line Items]
Useful life of Intangible assets, in years	17 years
Maximum | Trade names
Summary Of Significant Accounting Policies [Line Items]
Useful life of Intangible assets, in years	30 years
Maximum | Non-complete agreement
Summary Of Significant Accounting Policies [Line Items]
Useful life of Intangible assets, in years	6 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	5 years
Customer Concentration Risk [Member] | Sales Revenue, Net | Hospitals And Healthcare Providers
Summary Of Significant Accounting Policies [Line Items]
Concentration risk, percentage	87.00%
Customer Concentration Risk [Member] | Sales Revenue, Net | Other Medical Device Manufacturers
Summary Of Significant Accounting Policies [Line Items]
Concentration risk, percentage	9.00%
Customer Concentration Risk [Member] | Sales Revenue, Net | Home Care Providers such as Pharmacies
Summary Of Significant Accounting Policies [Line Items]
Concentration risk, percentage	4.00%