Stockholders' Equity (Details) - Reconciliation of the activity in Stockholders` Equity accounts (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 28, 2014	Jun. 29, 2013	Jun. 28, 2014	Jun. 29, 2013
Stockholders' Equity (Details) - Reconciliation of the activity in Stockholders` Equity accounts [Line Items]
Balance, December 31, 2013			$ 75,641
Net loss	(19,060)	(3,529)	(23,470)	(5,623)
Stock-based compensation			455	450
Adjustment to net periodic benefit cost	34	34	69	67
Balance, June 28, 2014	52,557		52,557
Common Stock [Member]
Stockholders' Equity (Details) - Reconciliation of the activity in Stockholders` Equity accounts [Line Items]
Balance, December 31, 2013			283
Net loss
Stock-based compensation
Exercise of stock options
Adjustment to net periodic benefit cost
Balance, June 28, 2014	283		283
Additional Paid-in Capital [Member]
Stockholders' Equity (Details) - Reconciliation of the activity in Stockholders` Equity accounts [Line Items]
Balance, December 31, 2013			15,732
Net loss
Stock-based compensation			455
Exercise of stock options
Adjustment to net periodic benefit cost
Balance, June 28, 2014	16,187		16,187
Retained Earnings [Member]
Stockholders' Equity (Details) - Reconciliation of the activity in Stockholders` Equity accounts [Line Items]
Balance, December 31, 2013			59,784
Net loss			(23,470)
Stock-based compensation
Exercise of stock options
Adjustment to net periodic benefit cost
Balance, June 28, 2014	36,314		36,314
Accumulated Other Comprehensive Income (Loss) [Member]
Stockholders' Equity (Details) - Reconciliation of the activity in Stockholders` Equity accounts [Line Items]
Balance, December 31, 2013			(158)
Net loss
Stock-based compensation
Exercise of stock options
Adjustment to net periodic benefit cost			(69)
Balance, June 28, 2014	$ (227)		$ (227)