Business segment information - additional information (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended				9 Months Ended
	Sep. 28, 2014		Sep. 29, 2013		Sep. 28, 2014 segment		Sep. 29, 2013		Dec. 31, 2013
Revenues from External Customers and Long-Lived Assets [Line Items]
Number of reportable segments					6
Revenue	$ 457,173		$ 413,796		$ 1,363,824		$ 1,245,732
Operating profit	81,935		66,042		215,707		179,197
Depreciation and amortization	32,439		27,075		96,254		79,035
Property, plant and equipment, net	347,233				347,233				325,900
United States
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	231,278		205,049		676,088		623,397
Property, plant and equipment, net	201,045				201,045				203,985
Other Americas
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	14,440		12,108		44,399		40,786
Europe
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	157,797		137,848		500,763		419,062
Czech Republic
Revenues from External Customers and Long-Lived Assets [Line Items]
Property, plant and equipment, net	38,728				38,728				41,607
Malaysia
Revenues from External Customers and Long-Lived Assets [Line Items]
Property, plant and equipment, net	35,972				35,972				29,313
All Other
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	53,658		58,791		142,574		162,487
Property, plant and equipment, net	71,488				71,488				50,995
Operating Segments
Revenues from External Customers and Long-Lived Assets [Line Items]
Operating profit	99,372	[1]	77,639	[1]	277,563	[1]	227,397	[1]
Unallocated expenses
Revenues from External Customers and Long-Lived Assets [Line Items]
Operating profit	(17,437)	[2]	(11,597)	[2]	(61,856)	[2]	(48,200)	[2]
Vascular North America
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	63,792		55,058		190,485		168,478
Depreciation and amortization	7,921		7,222		23,842		20,656
Vascular North America | Operating Segments
Revenues from External Customers and Long-Lived Assets [Line Items]
Operating profit	11,870		6,042		31,250		17,394
Anesthesia Respiratory North America
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	54,699		53,842		164,462		170,532
Depreciation and amortization	5,321		3,948		13,457		10,663
Anesthesia Respiratory North America | Operating Segments
Revenues from External Customers and Long-Lived Assets [Line Items]
Operating profit	9,421		3,541		21,401		18,483
Surgical North America
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	36,127		34,147		109,327		108,584
Depreciation and amortization	909		2,476		4,944		7,708
Surgical North America | Operating Segments
Revenues from External Customers and Long-Lived Assets [Line Items]
Operating profit	12,394		10,333		37,308		37,646
EMEA
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	141,146		132,265		446,061		412,525
Depreciation and amortization	9,688		7,035		28,298		20,666
EMEA | Operating Segments
Revenues from External Customers and Long-Lived Assets [Line Items]
Operating profit	28,810		21,074		85,771		65,542
Asia
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	62,035		55,263		174,176		148,040
Depreciation and amortization	2,003		1,134		6,146		3,506
Asia | Operating Segments
Revenues from External Customers and Long-Lived Assets [Line Items]
Operating profit	14,785		18,894		44,718		44,961
OEM
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	39,174		33,774		108,966		97,222
Depreciation and amortization	1,651		1,123		4,715		3,370
OEM | Operating Segments
Revenues from External Customers and Long-Lived Assets [Line Items]
Operating profit	9,651		6,684		24,551		20,778
All Other
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	60,200		49,447		170,347		140,351
Depreciation and amortization	4,946		4,137		14,852		12,466
All Other | Operating Segments
Revenues from External Customers and Long-Lived Assets [Line Items]
Operating profit	$ 12,441		$ 11,071		$ 32,564		$ 22,593

[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 other impairment charges.