Restructuring and other impairment charges - by segment (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Restructuring Cost and Reserve [Line Items]
Total restructuring charges	$ 14,790	$ 15,871	$ 7,819
Vascular North America
Restructuring Cost and Reserve [Line Items]
Total restructuring charges	2,595	5,843	3,049
Interventional North America
Restructuring Cost and Reserve [Line Items]
Total restructuring charges	4,908	459	1,894
Anesthesia North America
Restructuring Cost and Reserve [Line Items]
Total restructuring charges	1,262	1,839	384
Surgical North America
Restructuring Cost and Reserve [Line Items]
Total restructuring charges	0	151	397
EMEA
Restructuring Cost and Reserve [Line Items]
Total restructuring charges	5,722	4,423	4
Asia
Restructuring Cost and Reserve [Line Items]
Total restructuring charges	0	0	313
OEM
Restructuring Cost and Reserve [Line Items]
Total restructuring charges	0	795	61
All other
Restructuring Cost and Reserve [Line Items]
Total restructuring charges	$ 303	$ 2,361	$ 1,717