CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Millions	6 Months Ended
	Jun. 25, 2017	Jun. 26, 2016
Operating activities:
Net loss	$ (16.2)	$ (32.6)
Loss from discontinued operations	0.1	0.1
Loss from continuing operations	(16.1)	(32.5)
Adjustments to reconcile loss from continuing operations to net cash used in operating activities from continuing operations:
Depreciation and amortization	11.0	11.7
Stock-based compensation	4.0	3.1
Deferred income taxes	2.3	2.0
Amortization of deferred financing costs	0.7	0.8
Amortization of discount on Senior Secured Notes	0.4	0.4
Loss on extinguishment of debt	2.1	0.0
Provision for doubtful accounts	0.0	0.2
Litigation related charges	0.0	1.7
Provision for non-cash restructuring charges	0.0	7.7
Changes in assets and liabilities, net of acquisitions:
Accounts receivable	2.9	(6.2)
Inventoried costs	(7.4)	(3.2)
Prepaid expenses and other assets	(7.0)	0.6
Accounts payable	4.4	(1.3)
Accrued expenses	(4.7)	(2.0)
Accrued compensation	(3.6)	(2.7)
Advance payments received on contracts	1.4	5.9
Accrued interest	(0.5)	0.0
Billings in excess of costs and earnings on uncompleted contracts	(1.5)	0.9
Income tax receivable and payable	1.3	0.1
Other liabilities	(1.0)	0.4
Net cash used in operating activities from continuing operations	(11.3)	(12.4)
Investing activities:
Change in restricted cash	0.2	0.0
Capital expenditures	(12.7)	(3.5)
Proceeds from sale of assets	0.6	0.0
Net cash used in investing activities from continuing operations	(11.9)	(3.5)
Financing activities:
Extinguishment of long-term debt	(64.0)	0.0
Proceeds from the issuance of common stock	81.7	0.0
Repayment of debt	(0.5)	(0.5)
Proceeds from exercise of restricted stock units, employee stock options, and employee stock purchase plan	0.6	1.0
Net cash provided by financing activities from continuing operations	17.8	0.5
Net cash flows of continuing operations	(5.4)	(15.4)
Net operating cash flows of discontinued operations	(0.1)	0.1
Net investing cash flows of discontinued operations	(0.4)	4.5
Effect of exchange rate changes on cash and cash equivalents	0.1	(0.1)
Net decrease in cash and cash equivalents	(5.8)	(10.9)
Cash and cash equivalents at beginning of period	69.1	28.5
Cash and cash equivalents at end of period	$ 63.3	$ 17.6