Segment information (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Oct. 01, 2017	Sep. 25, 2016	Oct. 01, 2017	Sep. 25, 2016
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	$ 534,703	$ 455,648	$ 1,551,197	$ 1,354,094
Operating profit	110,354	86,487	281,375	252,425
Operating Segments
Revenues from External Customers and Long-Lived Assets [Line Items]
Operating profit	123,161	98,078	340,261	299,888
Unallocated expenses
Revenues from External Customers and Long-Lived Assets [Line Items]
Operating profit	(12,807)	(11,591)	(58,886)	(47,463)
Vascular North America
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	90,979	85,118	278,350	254,817
Vascular North America | Operating Segments
Revenues from External Customers and Long-Lived Assets [Line Items]
Operating profit	25,212	21,781	75,286	63,431
Anesthesia North America
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	50,819	48,670	148,107	143,821
Anesthesia North America | Operating Segments
Revenues from External Customers and Long-Lived Assets [Line Items]
Operating profit	15,684	13,954	49,727	41,181
Surgical North America
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	40,804	41,827	131,464	123,904
Surgical North America | Operating Segments
Revenues from External Customers and Long-Lived Assets [Line Items]
Operating profit	13,618	14,050	47,285	39,654
EMEA
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	131,517	121,398	394,212	375,198
EMEA | Operating Segments
Revenues from External Customers and Long-Lived Assets [Line Items]
Operating profit	24,187	16,576	69,677	61,563
Asia
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	72,387	64,087	185,328	176,434
Asia | Operating Segments
Revenues from External Customers and Long-Lived Assets [Line Items]
Operating profit	20,217	18,072	49,619	52,831
OEM
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	48,589	41,418	137,067	115,693
OEM | Operating Segments
Revenues from External Customers and Long-Lived Assets [Line Items]
Operating profit	12,256	10,201	31,714	24,605
All other
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	99,608	53,130	276,669	164,227
All other | Operating Segments
Revenues from External Customers and Long-Lived Assets [Line Items]
Operating profit	$ 11,987	$ 3,444	$ 16,953	$ 16,623