Income taxes (Components of provision) (Details) - USD ($) $ in Thousands	12 Months Ended
	Jan. 02, 2016	Jan. 03, 2015	Dec. 28, 2013
Current Income Tax Expense (Benefit)	$ 318	$ 15,690	$ 5,384
Deferred Income Tax Expense Benefit	(3,708)	(3,647)	3,039
Income Tax Expense (Benefit), Continuing Operations, Total	(3,390)	12,043	8,423
US
Current Income Tax Expense (Benefit)	(1,982)	14,626	5,175
Deferred Income Tax Expense Benefit	(5,971)	(6,397)	1,000
CA
Current Income Tax Expense (Benefit)	0	0	400
Deferred Income Tax Expense Benefit	2,484	2,741	2,583
Europe And Other [Member]
Current Income Tax Expense (Benefit)	2,300	1,064	(191)
Deferred Income Tax Expense Benefit	$ (221)	$ 9	$ (544)