Consolidated Statement of Stockholders' Equity - USD ($)	Total	Common Stock [Member]	Preferred Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Treasury Stock [Member]
Balance at Dec. 29, 2013	$ 77,204,000	$ 230,000	$ 0	$ 69,258,000	$ 7,155,000	$ 702,000	$ (141,000)
Common stock, shares outstanding at Dec. 29, 2013		23,048,334
Stock-based compensation	1,180,000	$ 0	0	1,180,000	0	0	0
Vesting of non-vested shares and excess tax benefits	0	$ 3,000	0	(3,000)	0	0	0
Vesting of non-vested shares, shares		278,906
Issuance of common stock	$ 67,327,000	$ 115,000	0	67,212,000	0	0	0
Issuance of common stock, shares	11,500,000	11,500,000
Net income (loss)	$ (38,117,000)	$ 0	0	0	(38,117,000)	0	0
Change in postretirement benefit obligations	(1,059,000)	0	0	0	0	(1,059,000)	0
Balance at Dec. 28, 2014	106,535,000	$ 348,000	0	137,647,000	(30,962,000)	(357,000)	(141,000)
Common stock, shares outstanding at Dec. 28, 2014		34,827,240
Stock-based compensation	1,438,000	$ 0	0	1,438,000	0	0	0
Vesting of non-vested shares and excess tax benefits	0	$ 2,000	0	(2,000)	0	0	0
Vesting of non-vested shares, shares		212,650
Net income (loss)	4,000	$ 0	0	0	4,000	0	0
Change in postretirement benefit obligations	22,000	0	0	0	0	22,000	0
Balance at Jan. 03, 2016	$ 107,999,000	$ 350,000	0	139,083,000	(30,958,000)	(335,000)	(141,000)
Common stock, shares outstanding at Jan. 03, 2016	35,039,890	35,039,890
Stock-based compensation	$ 2,053,000	$ 0	0	2,053,000	0	0	0
Vesting of non-vested shares and excess tax benefits	0	$ 3,000	0	(3,000)	0	0	0
Vesting of non-vested shares, shares		218,689
Net income (loss)	45,472,000	$ 0	0	0	45,472,000	0	0
Change in postretirement benefit obligations	(868,000)	0	0	0	0	(868,000)	0
Balance at Jan. 01, 2017	$ 154,656,000	$ 353,000	$ 0	$ 141,133,000	$ 14,514,000	$ (1,203,000)	$ (141,000)
Common stock, shares outstanding at Jan. 01, 2017	35,258,579	35,258,579