Goodwill and other intangible assets - components of intangible assets (Detail) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 2,964,632	$ 1,564,359
Accumulated Amortization	(580,884)	(472,696)
Customer relationships
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	1,023,837	622,428
Accumulated Amortization	(281,263)	(239,055)
In-process research and development
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	34,672	16,532
Accumulated Amortization	0	0
Intellectual property
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	1,287,487	519,962
Accumulated Amortization	(258,580)	(203,390)
Distribution rights
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	23,697	23,021
Accumulated Amortization	(16,996)	(15,239)
Trade names
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	571,510	379,724
Accumulated Amortization	(22,069)	(13,974)
Non-compete agreements
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	23,429	2,692
Accumulated Amortization	$ (1,976)	$ (1,038)