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	$ 285					285
Employee stock purchase plan (in shares)	96
Stock incentive plan	$ 3,093	(2,731)				362
Stock incentive plan (in shares)	338
Withholding taxes on stock-based awards		(382)				(382)
Stock-based compensation		2,835				2,835
Dividends on preferred stock			(3,400)			(3,400)
Accretion on preferred stock			(596)			(596)
Net earnings (loss)			16,594		89	16,683
Currency translation adjustment				(841)	2	(839)
Capital contribution to majority-owned subsidiary					203	203
Balance at Jun. 29, 2019	$ 317,735	31,518	(193,553)	(10,508)	1,798	146,990
Balance (in shares) at Jun. 29, 2019	87,857
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
Employee stock purchase plan	$ 137					137
Employee stock purchase plan (in shares)	40
Stock incentive plan	$ 2,396	(2,197)				199
Stock incentive plan (in shares)	242
Withholding taxes on stock-based awards		(299)				(299)
Stock-based compensation		2,998				2,998
Dividends on preferred stock			(1,700)			(1,700)
Accretion on preferred stock			(301)			(301)
Net earnings (loss)			(9,055)		143	(8,912)
Currency translation adjustment				249	(6)	243
Capital contribution to majority-owned subsidiary					203	203
Balance at Jun. 29, 2019	$ 317,735	31,518	(193,553)	(10,508)	1,798	146,990
Balance (in shares) at Jun. 29, 2019	87,857
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	$ 195					195
Employee stock purchase plan (in shares)	73
Stock incentive plan	$ 4,761	(4,385)				376
Stock incentive plan (in shares)	1,240
Withholding taxes on stock-based awards		(1,151)				(1,151)
Stock-based compensation		4,379				4,379
Dividends on preferred stock			(3,881)			(3,881)
Accretion on preferred stock			(748)			(748)
Net earnings (loss)			4,368		(244)	4,124
Currency translation adjustment				108	(7)	101
Balance at Jun. 27, 2020	$ 323,412	34,610	(215,192)	(11,163)	1,637	133,304
Balance (in shares) at Jun. 27, 2020	89,403
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
Employee stock purchase plan	$ 95					95
Employee stock purchase plan (in shares)	26
Stock incentive plan	$ 4,359	(4,105)				254
Stock incentive plan (in shares)	1,152
Withholding taxes on stock-based awards		(1,030)				(1,030)
Stock-based compensation		1,932				1,932
Dividends on preferred stock			(2,181)			(2,181)
Accretion on preferred stock			(423)			(423)
Net earnings (loss)			1,007		(230)	777
Currency translation adjustment				417	(10)	407
Balance at Jun. 27, 2020	$ 323,412	$ 34,610	$ (215,192)	$ (11,163)	$ 1,637	$ 133,304
Balance (in shares) at Jun. 27, 2020	89,403