Product Warranty and Safety Recall Campaigns (Narrative) (Detail) - USD ($) $ in Thousands	3 Months Ended
	Apr. 01, 2018	Dec. 31, 2017	Mar. 26, 2017	Dec. 31, 2016
Product Information [Line Items]
Liability for recall campaigns	$ 95,075	$ 94,202	$ 78,211	$ 79,482
Recall Campaign
Product Information [Line Items]
Liability for recall campaigns	$ 32,300	$ 35,300	$ 10,300
Motorcycles | All Countries, Excluding Japan
Product Information [Line Items]
Standard product warranty, period (in years)	2 years
Motorcycles | Japan
Product Information [Line Items]
Standard product warranty, period (in years)	3 years
Parts and Accessories and General Merchandise
Product Information [Line Items]
Standard product warranty, period (in years)	1 year