Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Millions	6 Months Ended
	Jul. 01, 2021	Jul. 02, 2020
Operating activities
Net loss	$ (306.9)	$ (418.9)
Adjustments to reconcile net loss to net cash used in operating activities
Depreciation and amortization expense	160.3	135.4
Amortization of deferred financing fees	4.3	5.5
Accretion of customer supply agreement	1.1	1.2
Employee Benefit and Share-based Payment Arrangement, Noncash	13.4	10.8
Loss on Derivative Instruments, Pretax	(0.1)	0.1
Loss (gain) from foreign currency transactions	4.9	(3.1)
Gain (Loss) on Disposition of Property Plant Equipment, Excluding Oil and Gas Property and Timber Property	(1.4)	(23.6)
Deferred taxes	12.5	(51.3)
Increase (Decrease) in Obligation, Pension and Other Postretirement Benefits	(30.5)	65.9
Grant liability amortization	(0.8)	(2.8)
Unrealized Gain (Loss) on Investments	1.0	3.0
Increase (Decrease) in Forward Provision	(28.1)	149.0
Changes in assets and liabilities
Accounts receivable, net	(11.2)	244.4
Inventory, net	111.8	(115.4)
Increase (Decrease) in Unbilled Receivables	14.4	209.7
Accounts payable and accrued liabilities	(11.3)	(551.8)
Profit sharing/deferred compensation	(29.2)	(60.1)
Advance payments	(1.3)	(19.8)
Income taxes receivable/payable	8.3	(211.8)
Increase (Decrease) in Billing in Excess of Cost of Earnings	(82.1)	(5.5)
Other	(29.6)	32.2
Net cash used in operating activities	(197.7)	(559.7)
Investing activities
Purchase of property, plant and equipment	(53.3)	(51.2)
Payments to Acquire Businesses, Net of Cash Acquired	(21.1)	(117.9)
Payments for (Proceeds from) Other Investing Activities	2.2	2.7
Net cash used in investing activities	(72.2)	(166.4)
Financing activities
Proceeds from (Repayments of) Other Debt	(5.0)	10.0
Proceeds from Issuance of Senior Long-term Debt	0.0	1,200.0
Principal payments of debt	(19.9)	(14.8)
Repayments of Debt	(2.0)	(11.4)
Repayments of Lines of Credit	0.0	(800.0)
Repayments of Senior Debt	300.0	0.0
Payment, Tax Withholding, Share-based Payment Arrangement	(4.4)	(13.8)
Proceeds from Stock Plans	1.4	1.3
Debt issuance and financing costs	0.0	(24.5)
Proceeds from (Repurchase of) Equity	0.0	0.1
Payments of Dividends	(2.2)	(13.4)
Proceeds from (Payments for) Other Financing Activities	0.1	0.0
Net cash (used in) provided by financing activities	(332.0)	333.5
Effect of exchange rate changes on cash and cash equivalents	(2.1)	(7.7)
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents, Period Increase (Decrease), Including Exchange Rate Effect	(604.0)	(400.3)
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents, Beginning Balance	1,893.1	2,367.2
Cash, cash equivalents, and restricted cash, end of period	1,289.1	1,966.9
Cash and Cash Equivalents, at Carrying Value, Ending Balance	1,269.3	1,947.1
Reconciliation of Cash, Cash Equivalents, and Restricted Cash [Abstract]
Restricted Cash, Current	0.3	0.3
Restricted Cash, Noncurrent	19.5	19.5
Increase (Decrease) in Income Taxes Payable	8.3	(211.8)
Payments to Acquire Businesses, Net of Cash Acquired	21.1	117.9
Proceeds from Issuance of Senior Long-term Debt	0.0	1,200.0
Repayments of Lines of Credit	0.0	800.0
Repayments of Senior Debt	300.0	0.0
Proceeds from (Payments for) Other Financing Activities	0.1	0.0
Payments for Repurchase of Common Stock	$ 0.0	$ 0.1