Income Taxes (Income Tax Expense) (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 29, 2019	Sep. 29, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 30, 2018	Sep. 30, 2018	Jul. 01, 2018	Apr. 01, 2018	Dec. 29, 2019	Dec. 30, 2018	Dec. 31, 2017
Current income tax expense (benefit):
Canada									$ 7,600	$ 7,997	$ 7,293
Foreign									6,417	5,253	(623)
Total current income tax expense									14,017	13,250	6,670
Deferred income tax expense (benefit):
Canada									1,497	122	(22,287)
Foreign									1,795	10,441	(11,943)
Total deferred income tax expense (benefit)									3,292	10,563	(34,230)
Income tax expense (benefit)	$ 2,624	$ 4,334	$ 10,293	$ 58	$ 3,067	$ 6,151	$ 7,894	$ 6,701	$ 17,309	$ 23,813	$ (27,560)