Business segment information - additional information (Details) $ in Thousands			3 Months Ended		6 Months Ended
		Apr. 01, 2015 segment	Jun. 28, 2015 USD ($)	Jun. 29, 2014 USD ($)	Jun. 28, 2015 USD ($) segment	Jun. 29, 2014 USD ($)	Dec. 31, 2014 USD ($)
Revenues from External Customers and Long-Lived Assets [Line Items]
Number of operating segments | segment					6
Revenue			$ 452,045	$ 468,105	$ 881,475	$ 906,651
Operating profit			76,986	74,752	142,594	133,772
Depreciation and amortization			30,782	32,402	60,632	63,815
Property, plant and equipment, net			315,536		315,536		$ 317,435
United States
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue			238,518	228,349	469,724	444,810
Property, plant and equipment, net			177,772		177,772		174,893
Other Americas
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue			15,122	15,187	28,563	29,959
Europe
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue			143,692	174,193	284,375	342,967
Malaysia
Revenues from External Customers and Long-Lived Assets [Line Items]
Property, plant and equipment, net			35,594		35,594		36,427
Czech Republic
Revenues from External Customers and Long-Lived Assets [Line Items]
Property, plant and equipment, net			33,612		33,612		35,655
All Other
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue			54,713	50,376	98,813	88,915
Property, plant and equipment, net			68,558		68,558		$ 70,460
Operating Segments
Revenues from External Customers and Long-Lived Assets [Line Items]
Operating profit	[1]		96,319	96,474	179,973	178,191
Unallocated expenses
Revenues from External Customers and Long-Lived Assets [Line Items]
Operating profit	[2]		(19,333)	(21,722)	(37,379)	(44,419)
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
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue			81,165	77,203	161,931	152,062
Depreciation and amortization			9,265	9,061	18,413	17,932
Vascular North America | Operating Segments
Revenues from External Customers and Long-Lived Assets [Line Items]
Operating profit			17,055	13,544	32,805	25,709
Anesthesia North America
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue			45,579	45,730	91,028	88,982
Depreciation and amortization			1,552	3,111	3,194	6,355
Anesthesia North America | Operating Segments
Revenues from External Customers and Long-Lived Assets [Line Items]
Operating profit			11,434	8,399	21,394	15,364
Surgical North America
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue			40,520	37,969	78,579	73,200
Depreciation and amortization			2,348	1,666	4,826	4,035
Surgical North America | Operating Segments
Revenues from External Customers and Long-Lived Assets [Line Items]
Operating profit			14,315	14,366	26,642	24,914
EMEA
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue			129,132	154,670	258,414	304,915
Depreciation and amortization			8,342	9,673	16,240	18,610
EMEA | Operating Segments
Revenues from External Customers and Long-Lived Assets [Line Items]
Operating profit			19,343	30,080	45,678	56,961
Asia
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue			62,042	62,539	110,571	112,141
Depreciation and amortization			3,010	2,305	5,408	4,143
Asia | Operating Segments
Revenues from External Customers and Long-Lived Assets [Line Items]
Operating profit			18,951	17,096	27,097	29,933
OEM
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue			37,918	36,610	72,633	69,792
Depreciation and amortization			1,704	1,608	3,371	3,064
OEM | Operating Segments
Revenues from External Customers and Long-Lived Assets [Line Items]
Operating profit			8,366	8,296	16,409	14,900
All Other
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue			55,689	53,384	108,319	105,559
Depreciation and amortization			4,561	4,978	9,180	9,676
All Other | Operating Segments
Revenues from External Customers and Long-Lived Assets [Line Items]
Operating profit			$ 6,855	$ 4,693	$ 9,948	$ 10,410

[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, and restructuring and impairment charges.