Reconciliation of Previously Reported Amonts to Amounts as Restated - Consolidated Condensed Statement of Equity (Details) - USD ($) $ in Thousands	3 Months Ended						6 Months Ended		9 Months Ended	12 Months Ended
	Jun. 27, 2015	Mar. 28, 2015	Dec. 31, 2014	Sep. 27, 2014	Jun. 28, 2014	Mar. 29, 2014	Jun. 27, 2015	Jun. 28, 2014	Sep. 27, 2014	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance, beginning		$ 199,885				$ 206,179	$ 199,885	$ 206,179	$ 206,179	$ 206,179
Net earnings (loss)	$ 1,460	847	$ (4,818)	$ 3,264	$ 3,570	1,242	2,307	4,812	8,076	3,258	$ 4,492	$ 12,291
Other comprehensive loss							(2,551)
Balance, ending	193,699		199,885				193,699			199,885	206,179
As previously reported
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance, beginning		201,158				203,551	201,158	203,551	203,551	203,551
Net earnings (loss)		683	(4,344)	3,149	3,453	1,773		5,226	8,375	4,031	4,347	11,764
Balance, ending			201,158							201,158	203,551
Correction of prior period misstatements
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance, beginning		(1,273)				2,628	(1,273)	2,628	2,628	2,628
Net earnings (loss)		164	(474)	$ 115	$ 117	(531)		(414)	(299)	(773)	145	527
Balance, ending			(1,273)							(1,273)	2,628
Retained Earnings
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance, beginning		35,335				32,255	35,335	32,255	32,255	32,255	27,819
Net earnings (loss)							2,336			3,080	4,436
Balance, ending	37,671		35,335				37,671			35,335	32,255	27,819
Retained Earnings | As previously reported
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance, beginning		36,500				32,647	36,500	32,647	32,647	32,647	28,356
Net earnings (loss)										3,853	4,291
Balance, ending			36,500							36,500	32,647	28,356
Retained Earnings | Correction of prior period misstatements
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance, beginning		(1,165)				(392)	(1,165)	(392)	(392)	(392)	(537)
Net earnings (loss)										(773)	145
Balance, ending			(1,165)							(1,165)	(392)	(537)
Accumulated Other Comprehensive Income (Loss)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance, beginning		(26,560)				(16,007)	(26,560)	(16,007)	(16,007)	(16,007)	(13,216)
Other comprehensive loss							(2,551)			(10,553)	(2,791)
Balance, ending	$ (29,111)		(26,560)				(29,111)			(26,560)	(16,007)	(13,216)
Accumulated Other Comprehensive Income (Loss) | As previously reported
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance, beginning		(26,452)				(19,027)	(26,452)	(19,027)	(19,027)	(19,027)	(14,983)
Other comprehensive loss										(7,425)	(4,044)
Balance, ending			(26,452)							(26,452)	(19,027)	(14,983)
Accumulated Other Comprehensive Income (Loss) | Correction of prior period misstatements
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance, beginning		$ (108)				$ 3,020	$ (108)	$ 3,020	$ 3,020	3,020	1,767
Other comprehensive loss										(3,128)	1,253
Balance, ending			$ (108)							$ (108)	$ 3,020	$ 1,767