CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2024	Jun. 25, 2023
Operating activities:
Net income (loss) from consolidated operations	$ 9.2	$ (6.2)
Adjustments to reconcile net income (loss) from consolidated operations to net cash used in operating activities:
Depreciation and amortization	19.7	15.8
Deferred income taxes	0.1	0.1
Amortization of lease right-of-use assets	6.0	5.5
Stock-based compensation	15.8	12.6
Amortization of deferred financing costs	0.3	0.3
Provision for doubtful accounts	0.0	0.9
Changes in assets and liabilities:
Accounts receivable	(3.0)	(10.7)
Unbilled receivables	(6.4)	(7.1)
Inventoried costs	2.1	(20.0)
Prepaid expenses and other assets	(18.8)	(9.7)
Operating lease liabilities	(6.1)	(5.2)
Accounts payable	(3.6)	2.2
Accrued expenses	0.0	7.2
Accrued compensation	(1.5)	2.0
Accrued interest	(0.6)	(0.1)
Billings in excess of costs and earnings on uncompleted contracts	(21.0)	11.2
Income tax receivable and payable	4.4	0.6
Other liabilities	1.4	(1.6)
Net cash used in operating activities	(2.0)	(2.2)
Investing activities:
Cash paid for acquisitions, net of cash acquired	(11.5)	0.0
Proceeds from sale of assets	0.0	8.3
Capital expenditures	(29.3)	(18.9)
Net cash used in investing activities	(40.8)	(10.6)
Financing activities:
Proceeds from the issuance of common stock, net of issuance costs	330.7	0.0
Borrowing under credit facility	10.0	34.0
Repayment under credit facility and term loan	(47.5)	(53.5)
Payments under finance leases	(0.7)	(0.8)
Payments of employee taxes withheld from share-based awards	(17.1)	(3.4)
Proceeds from shares issued under equity plans	3.6	2.9
Net cash provided by (used in) financing activities	279.0	(20.8)
Net cash provided (used)	236.2	(33.6)
Effect of exchange rate changes on cash and cash equivalents	(0.8)	0.5
Net increase (decrease) in cash and cash equivalents	235.4	(33.1)
Cash and cash equivalents at beginning of period	72.8	81.3
Cash and cash equivalents at end of period	308.2	48.2
Significant non-cash investing and financing activities:
Financing lease obligation incurred	16.8	0.1
Capital expenditures included in accounts payable and accrued expenses	2.5	1.6
Common stock issuance for purchase of noncontrolling interests	$ 11.3	$ 10.7