Restatement - Statement of Cash Flows (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Oct. 03, 2015	Sep. 27, 2014	Oct. 03, 2015	Sep. 27, 2014
Cash Flows from Operating Activities
Net (Loss) Income	$ (9,515)	$ 2,933	$ (9,706)	$ 14,711
Adjustments to Reconcile Net Income to Net Cash Provided by Operating Activities
Depreciation and amortization	6,635	6,704	20,064	21,829
Stock-based compensation expense			2,792	2,520
Deferred income taxes			1,599	2,073
Excess tax benefits from stock-based compensation			(516)	(139)
Recovery of doubtful accounts			(11)	(214)
Other			7,180	(149)
Changes in Assets and Liabilities:
Accounts receivable			4,836	(12,273)
Inventories			5,525	(4,961)
Production cost of contracts			(560)	(1,408)
Other assets			1,614	6,633
Accounts payable			(7,626)	(2,447)
Accrued and other liabilities			(18,076)	(5,400)
Net Cash Provided by Operating Activities			12,085	20,775
Cash Flows from Investing Activities
Purchases of property and equipment			(11,803)	(9,329)
Proceeds from sale of assets			289	83
Insurance recoveries related to property and equipment			1,510	1,600
Net Cash Used in Investing Activities			(10,004)	(7,646)
Cash Flows from Financing Activities
Repayments of senior unsecured notes and term loans			(305,000)	(22,500)
Repayments of other debt			(17)	(19)
Excess tax benefits from stock-based compensation			516	139
Net proceeds from issuance of common stock under stock plans			(1,118)	1,289
Net Cash Used in Financing Activities			(35,467)	(21,091)
Net (Decrease) Increase in Cash and Cash Equivalents			(33,386)	(7,962)
Cash and Cash Equivalents at Beginning of Period			45,627	48,814
Cash and Cash Equivalents at End of Period	$ 12,241	40,852	$ 12,241	40,852
As Reported
Cash Flows from Operating Activities
Net (Loss) Income		2,622		13,723
Adjustments to Reconcile Net Income to Net Cash Provided by Operating Activities
Depreciation and amortization				21,829
Stock-based compensation expense				2,520
Deferred income taxes				1,775
Excess tax benefits from stock-based compensation				(139)
Recovery of doubtful accounts				(214)
Other				649
Changes in Assets and Liabilities:
Accounts receivable				(12,273)
Inventories				(4,961)
Production cost of contracts				(1,408)
Other assets				7,121
Accounts payable				(2,447)
Accrued and other liabilities				(5,400)
Net Cash Provided by Operating Activities				20,775
Cash Flows from Investing Activities
Purchases of property and equipment				(9,329)
Proceeds from sale of assets				83
Insurance recoveries related to property and equipment				1,600
Net Cash Used in Investing Activities				(7,646)
Cash Flows from Financing Activities
Repayments of senior unsecured notes and term loans				(22,500)
Repayments of other debt				(19)
Excess tax benefits from stock-based compensation				139
Net proceeds from issuance of common stock under stock plans				1,289
Net Cash Used in Financing Activities				(21,091)
Net (Decrease) Increase in Cash and Cash Equivalents				(7,962)
Cash and Cash Equivalents at Beginning of Period				48,814
Cash and Cash Equivalents at End of Period		40,852		40,852
Adjustments
Cash Flows from Operating Activities
Net (Loss) Income		311		988
Adjustments to Reconcile Net Income to Net Cash Provided by Operating Activities
Depreciation and amortization				0
Stock-based compensation expense				0
Deferred income taxes				298
Excess tax benefits from stock-based compensation				0
Recovery of doubtful accounts				0
Other				(798)
Changes in Assets and Liabilities:
Accounts receivable				0
Inventories				0
Production cost of contracts				0
Other assets				(488)
Accounts payable				0
Accrued and other liabilities				0
Net Cash Provided by Operating Activities				0
Cash Flows from Investing Activities
Purchases of property and equipment				0
Proceeds from sale of assets				0
Insurance recoveries related to property and equipment				0
Net Cash Used in Investing Activities				0
Cash Flows from Financing Activities
Repayments of senior unsecured notes and term loans				0
Repayments of other debt				0
Excess tax benefits from stock-based compensation				0
Net proceeds from issuance of common stock under stock plans				0
Net Cash Used in Financing Activities				0
Net (Decrease) Increase in Cash and Cash Equivalents				0
Cash and Cash Equivalents at Beginning of Period				0
Cash and Cash Equivalents at End of Period		$ 0		$ 0