Consolidated Statements of Shareholders' Equity - USD ($) shares in Thousands, $ in Thousands	Common shares [Member]	Additional Paid-in Capital [Member]	Accumulated deficit [Member]	Accumulated other comprehensive loss [Member]	Non-controlling interest [Member]	Total
Balance at Dec. 31, 2017	$ 308,899	$ 28,006	$ (89,291)	$ (7,268)	$ 1,575	$ 241,921
Balance (in shares) at Dec. 31, 2017	86,757
Employee stock purchase plan	$ 136					136
Employee stock purchase plan (in shares)	23
Stock incentive plan	$ 540	(527)				13
Stock incentive plan (in shares)	60
Stock-based compensation		2,171				2,171
Dividends on Series A Preferred Stock			(1,700)			(1,700)
Accretion on Series A Preferred Stock			(267)			(267)
Net loss			(4,363)		(99)	(4,462)
Currency translation adjustment				1,336	120	1,456
Cash flow hedges, net of income taxes of $303				707		707
Balance at Mar. 31, 2018	$ 309,575	29,650	(95,367)	(5,225)	1,596	240,229
Balance (in shares) at Mar. 31, 2018	86,840
Cumulative effect of adoption of new revenue accounting standard			254			254
Balance at Dec. 29, 2018	$ 314,357	31,796	(206,151)	(9,667)	1,504	131,839
Balance (in shares) at Dec. 29, 2018	87,423
Employee stock purchase plan	$ 148					148
Employee stock purchase plan (in shares)	56
Stock incentive plan	$ 697	(534)				163
Stock incentive plan (in shares)	96
Withholding taxes on stock-based awards		(83)				(83)
Stock-based compensation		(163)				(163)
Dividends on Series A Preferred Stock			(1,700)			(1,700)
Accretion on Series A Preferred Stock			(295)			(295)
Net loss			25,649		(54)	25,595
Currency translation adjustment				(1,090)	8	(1,082)
Balance at Mar. 30, 2019	$ 315,202	$ 31,016	$ (182,497)	$ (10,757)	$ 1,458	$ 154,422
Balance (in shares) at Mar. 30, 2019	87,575