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 interests [Member]	Total
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 earnings			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
Balance at Dec. 28, 2019	$ 318,456	35,767	(214,931)	(11,271)	1,888	129,909
Balance (in shares) at Dec. 28, 2019	88,090
Employee stock purchase plan	$ 100					100
Employee stock purchase plan (in shares)	47
Stock incentive plan	$ 402	(280)				122
Stock incentive plan (in shares)	88
Withholding taxes on stock-based awards		(121)				(121)
Stock-based compensation		2,447				2,447
Dividends on Series A Preferred Stock			(1,700)			(1,700)
Accretion on Series A Preferred Stock			(325)			(325)
Net earnings			3,361		(14)	3,347
Currency translation adjustment				(309)	3	(306)
Balance at Mar. 28, 2020	$ 318,958	$ 37,813	$ (213,595)	$ (11,580)	$ 1,877	$ 133,473
Balance (in shares) at Mar. 28, 2020	88,225