Segment information (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Oct. 01, 2017	Sep. 30, 2018	Oct. 01, 2017
Revenues from External Customers and Long-Lived Assets [Line Items]
Net revenues	$ 609,672	$ 534,703	$ 1,806,768	$ 1,551,197
Operating profit	82,105	110,354	202,438	281,375
Operating Segments
Revenues from External Customers and Long-Lived Assets [Line Items]
Operating profit	126,358	123,161	347,550	340,261
Unallocated expenses
Revenues from External Customers and Long-Lived Assets [Line Items]
Operating profit	(44,253)	(12,807)	(145,112)	(58,886)
Vascular North America
Revenues from External Customers and Long-Lived Assets [Line Items]
Net revenues	80,719	75,065	243,829	232,872
Vascular North America | Operating Segments
Revenues from External Customers and Long-Lived Assets [Line Items]
Operating profit	24,287	17,803	73,585	54,565
Interventional North America
Revenues from External Customers and Long-Lived Assets [Line Items]
Net revenues	66,726	60,719	191,878	159,002
Interventional North America | Operating Segments
Revenues from External Customers and Long-Lived Assets [Line Items]
Operating profit	17,142	12,485	47,772	13,265
Anesthesia North America
Revenues from External Customers and Long-Lived Assets [Line Items]
Net revenues	53,160	50,819	154,215	148,107
Anesthesia North America | Operating Segments
Revenues from External Customers and Long-Lived Assets [Line Items]
Operating profit	16,811	15,084	48,860	48,444
Surgical North America
Revenues from External Customers and Long-Lived Assets [Line Items]
Net revenues	42,545	40,804	123,930	131,464
Surgical North America | Operating Segments
Revenues from External Customers and Long-Lived Assets [Line Items]
Operating profit	15,906	13,618	47,709	47,285
EMEA
Revenues from External Customers and Long-Lived Assets [Line Items]
Net revenues	139,541	137,034	452,826	409,077
EMEA | Operating Segments
Revenues from External Customers and Long-Lived Assets [Line Items]
Operating profit	21,916	24,198	80,221	69,102
Asia
Revenues from External Customers and Long-Lived Assets [Line Items]
Net revenues	76,544	74,202	207,201	190,368
Asia | Operating Segments
Revenues from External Customers and Long-Lived Assets [Line Items]
Operating profit	20,834	20,427	54,948	50,252
OEM
Revenues from External Customers and Long-Lived Assets [Line Items]
Net revenues	54,838	48,589	153,286	137,067
OEM | Operating Segments
Revenues from External Customers and Long-Lived Assets [Line Items]
Operating profit	15,049	12,256	37,617	31,714
All other
Revenues from External Customers and Long-Lived Assets [Line Items]
Net revenues	95,599	47,471	279,603	143,240
All other | Operating Segments
Revenues from External Customers and Long-Lived Assets [Line Items]
Operating profit	$ (5,587)	$ 7,290	$ (43,162)	$ 25,634