Restructuring (credits) charges - Charges by segment (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Oct. 01, 2017	Sep. 25, 2016	Oct. 01, 2017	Sep. 25, 2016
Restructuring Cost and Reserve [Line Items]
Restructuring charges	$ (92)	$ 3,027	$ 13,723	$ 12,876
Vascular North America
Restructuring Cost and Reserve [Line Items]
Restructuring charges	606	960	1,715	5,474
Anesthesia North America
Restructuring Cost and Reserve [Line Items]
Restructuring charges	220	946	1,031	3,185
Surgical North America
Restructuring Cost and Reserve [Line Items]
Restructuring charges	0	277	0	257
EMEA
Restructuring Cost and Reserve [Line Items]
Restructuring charges	(632)	89	6,503	3,012
OEM
Restructuring Cost and Reserve [Line Items]
Restructuring charges	0	187	0	191
All Other
Restructuring Cost and Reserve [Line Items]
Restructuring charges	$ (286)	$ 568	$ 4,474	$ 757