Segment information (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jul. 02, 2017	Jun. 26, 2016	Jul. 02, 2017	Jun. 26, 2016
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	$ 528,613	$ 473,553	$ 1,016,494	$ 898,446
Operating profit	110,202	98,441	171,021	165,938
Operating Segments
Revenues from External Customers and Long-Lived Assets [Line Items]
Operating profit	126,519	111,738	217,100	201,810
Unallocated expenses
Revenues from External Customers and Long-Lived Assets [Line Items]
Operating profit	(16,317)	(13,297)	(46,079)	(35,872)
Vascular North America
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	93,522	88,111	187,371	169,699
Vascular North America | Operating Segments
Revenues from External Customers and Long-Lived Assets [Line Items]
Operating profit	25,258	21,994	50,074	41,650
Anesthesia North America
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	49,081	49,194	97,288	95,151
Anesthesia North America | Operating Segments
Revenues from External Customers and Long-Lived Assets [Line Items]
Operating profit	20,516	15,050	34,043	27,227
Surgical North America
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	44,716	43,136	90,660	82,077
Surgical North America | Operating Segments
Revenues from External Customers and Long-Lived Assets [Line Items]
Operating profit	17,287	12,348	33,667	25,604
EMEA
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	131,962	131,705	262,695	253,800
EMEA | Operating Segments
Revenues from External Customers and Long-Lived Assets [Line Items]
Operating profit	23,250	23,944	45,490	44,987
Asia
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	63,988	63,191	112,941	112,347
Asia | Operating Segments
Revenues from External Customers and Long-Lived Assets [Line Items]
Operating profit	18,604	21,751	29,402	34,759
OEM
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	45,132	40,298	88,478	74,275
OEM | Operating Segments
Revenues from External Customers and Long-Lived Assets [Line Items]
Operating profit	10,337	9,215	19,458	14,404
All other
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	100,212	57,918	177,061	111,097
All other | Operating Segments
Revenues from External Customers and Long-Lived Assets [Line Items]
Operating profit	$ 11,267	$ 7,436	$ 4,966	$ 13,179