Business segment information - additional information (Details) $ in Thousands			3 Months Ended		9 Months Ended
		Apr. 01, 2015 segment	Sep. 27, 2015 USD ($)	Sep. 28, 2014 USD ($)	Sep. 27, 2015 USD ($) segment	Sep. 28, 2014 USD ($)	Dec. 31, 2014 USD ($)
Revenues from External Customers and Long-Lived Assets [Line Items]
Number of operating segments | segment					6
Revenue			$ 443,714	$ 457,173	$ 1,325,189	$ 1,363,824
Operating profit			76,550	81,935	219,144	215,707
Depreciation and amortization			31,343	32,439	91,975	96,254
Property, plant and equipment, net			313,244		313,244		$ 317,435
United States
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue			240,558	231,278	710,282	676,088
Property, plant and equipment, net			178,212		178,212		174,893
Other Americas
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue			12,961	14,440	41,524	44,399
Europe
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue			134,939	157,797	419,314	500,763
Malaysia
Revenues from External Customers and Long-Lived Assets [Line Items]
Property, plant and equipment, net			33,096		33,096		36,427
Czech Republic
Revenues from External Customers and Long-Lived Assets [Line Items]
Property, plant and equipment, net			33,051		33,051		35,655
All Other
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue			55,256	53,658	154,069	142,574
Property, plant and equipment, net			68,885		68,885		$ 70,460
Operating Segments
Revenues from External Customers and Long-Lived Assets [Line Items]
Operating profit	[1]		95,865	99,372	275,838	277,563
All Other
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue			52,072	54,826	160,391	160,385
Operating profit			5,551	6,464	15,499	16,874
Depreciation and amortization			4,722	6,476	13,902	16,152
Unallocated expenses
Revenues from External Customers and Long-Lived Assets [Line Items]
Operating profit	[2]		(19,315)	(17,437)	(56,694)	(61,856)
Anesthesia Respiratory North America
Revenues from External Customers and Long-Lived Assets [Line Items]
Number of operating segments as result of split | segment		2
Vascular North America | Operating Segments
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue			82,675	76,662	244,606	228,724
Operating profit			18,086	15,302	50,891	41,011
Depreciation and amortization			9,317	8,823	27,730	26,755
Anesthesia North America | Operating Segments
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue			47,628	47,203	138,656	136,185
Operating profit			15,178	11,966	36,572	27,330
Depreciation and amortization			1,992	2,889	5,186	9,244
Surgical North America | Operating Segments
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue			39,591	36,127	118,170	109,327
Operating profit			12,814	12,394	39,456	37,308
Depreciation and amortization			2,867	909	7,693	4,944
EMEA | Operating Segments
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue			120,854	141,146	379,268	446,061
Operating profit			19,656	28,810	65,334	85,771
Depreciation and amortization			7,848	9,688	24,088	28,298
Asia | Operating Segments
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue			61,935	62,035	172,506	174,176
Operating profit			15,715	14,785	42,812	44,718
Depreciation and amortization			2,870	2,003	8,278	6,146
OEM | Operating Segments
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue			38,959	39,174	111,592	108,966
Operating profit			8,865	9,651	25,274	24,551
Depreciation and amortization			$ 1,727	$ 1,651	$ 5,098	$ 4,715

[1] Segment operating profit includes segment net revenues from external customers reduced by its standard cost of goods sold, adjusted for fixed manufacturing cost absorption variances, selling, general and administrative expenses, research and development expenses and an allocation of corporate expenses. Corporate expenses are allocated among the segments in proportion to the respective amounts of one of several items (such as sales, numbers of employees, and amount of time spent), depending on the category of expense involved.

[2] Unallocated expenses primarily include manufacturing variances, with the exception of fixed manufacturing cost absorption variances, restructuring charge