CONDENSED CONSOLIDATED BALANCE SHEETS - USD ($) $ in Millions	Jun. 27, 2021	Dec. 27, 2020
Current assets:
Cash and cash equivalents	$ 369.3	$ 380.8
Restricted cash	0.0	0.7
Accounts receivable, net	80.0	95.3
Unbilled receivables, net	185.0	177.0
Inventoried costs	90.7	81.2
Prepaid expenses	13.4	12.0
Other current assets	30.3	17.8
Total current assets	768.7	764.8
Property, plant and equipment, net	145.5	143.8
Operating lease right-of-use assets	40.1	42.9
Goodwill	483.7	483.9
Intangible assets, net	40.4	43.0
Other assets	83.9	84.4
Total assets	1,562.3	1,562.8
Current liabilities:
Accounts payable	59.9	55.4
Accrued expenses	27.2	34.7
Accrued compensation	46.2	48.1
Accrued interest	1.5	1.5
Billings in excess of costs and earnings on uncompleted contracts	43.5	34.0
Current portion of operating lease liabilities	9.3	8.9
Other current liabilities	11.8	11.9
Current liabilities of discontinued operations	2.7	3.1
Total current liabilities	202.1	197.6
Long-term debt	300.3	301.0
Operating lease liabilities, net of current portion	35.3	38.6
Other long-term liabilities	71.6	83.0
Long-term liabilities of discontinued operations	2.5	2.5
Total liabilities	611.8	622.7
Commitments and contingencies
Redeemable noncontrolling interest	14.6	14.8
Stockholders’ equity:
Preferred stock, $0.001 par value, 5,000,000 shares authorized, 0 shares outstanding at June 27, 2021 and December 27, 2020	0.0	0.0
Common stock, $0.001 par value, 195,000,000 shares authorized; 123,807,616 and 123,047,147 shares issued and outstanding at June 27, 2021 and December 27, 2020, respectively	0.0	0.0
Additional paid-in capital	1,563.1	1,556.3
Accumulated other comprehensive income	2.2	1.4
Accumulated deficit	(629.4)	(632.4)
Total stockholders’ equity	935.9	925.3
Total liabilities and stockholders’ equity	$ 1,562.3	$ 1,562.8