CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Millions	12 Months Ended
	Dec. 29, 2024	Dec. 31, 2023	Dec. 25, 2022
Operating activities:
Net income (loss) from consolidated operations	$ 16.3	$ 2.4	$ (33.2)
Adjustments to reconcile income (loss) from consolidated operations to net cash provided by (used in) operating activities:
Depreciation and amortization	40.3	33.2	30.5
Deferred income taxes	4.4	2.5	(3.1)
Amortization of lease right-of-use assets	11.6	11.5	10.4
Stock-based compensation	29.8	25.3	26.3
Loss on extinguishment of debt	0.0	0.0	13.0
Amortization of deferred financing costs	0.7	0.7	0.8
Provision for doubtful accounts	0.0	1.0	0.0
Litigation settlement charges	0.0	0.0	5.5
Changes in assets and liabilities, net of acquisitions:
Accounts receivable	11.2	(13.1)	(4.9)
Unbilled receivables	(6.1)	14.4	(22.4)
Inventoried costs	(5.0)	(29.6)	(23.8)
Prepaid expenses	(1.8)	(3.9)	(1.9)
Other assets	(35.6)	(12.3)	(18.7)
Operating lease liabilities	(12.4)	(11.4)	(10.5)
Accounts payable	15.1	4.4	4.5
Accrued expenses	1.7	1.4	5.6
Accrued compensation	7.0	12.4	0.8
Billings in excess of costs and earnings on uncompleted contracts	(25.7)	28.4	2.7
Income tax receivable and payable	(0.3)	(0.5)	0.1
Other liabilities	(1.5)	(1.6)	(7.4)
Net cash provided by (used in) operating activities	49.7	65.2	(25.7)
Investing activities:
Cash paid for acquisitions, net of cash acquired	(11.5)	0.3	(132.2)
Proceeds from sale of assets	0.0	8.3	0.2
Capital expenditures	(58.2)	(52.4)	(45.4)
Net cash used in investing activities	(69.7)	(43.8)	(177.4)
Financing activities:
Proceeds from the issuance of long-term debt	0.0	0.0	200.0
Proceeds from the issuance of common stock, net of issuance costs	330.7	0.0	0.0
Borrowing under credit facility	10.0	69.0	100.0
Redemption of Senior Secured Notes	0.0	0.0	(309.8)
Repayment under credit facility, term loan and other debt	(52.5)	(101.0)	(42.5)
Payments of employee taxes withheld from share-based awards	(17.4)	(3.7)	(12.5)
Debt issuance costs	0.0	0.0	(3.3)
Payments under finance leases	(1.4)	(1.5)	(1.4)
Proceeds from shares issued under equity plans	8.2	6.5	6.2
Net cash provided by (used in) financing activities	277.6	(30.7)	(63.3)
Net cash provided (used)	257.6	(9.3)	(266.4)
Effect of exchange rate changes on cash and cash equivalents	(1.1)	0.8	(1.7)
Net increase (decrease) in cash and cash equivalents	256.5	(8.5)	(268.1)
Cash, and cash equivalents at beginning of year	72.8	81.3	349.4
Cash and cash equivalents at end of year	329.3	72.8	81.3
Supplemental disclosure of cash flow information:
Cash paid during the year for interest	14.6	19.6	13.7
Net cash paid during the year for income taxes	5.0	6.5	4.4
Non-cash financing and investing activities:
Financing lease obligations incurred	15.4	6.9	9.1
Capital expenditures included in accounts payable and accrued expenses	8.8	0.6	2.7
Common stock issuance for purchase of noncontrolling interests	11.3	10.7	2.7
Common stock issuance for acquisition	$ 0.5	$ 14.8	$ 5.0