Consolidated Balance Sheets (Unaudited) - USD ($) $ in Millions	Mar. 29, 2018	Dec. 31, 2017
Assets
Cash and cash equivalents	$ 437.9	$ 423.3
Restricted Cash and Cash Equivalents	0.4	2.2
Accounts receivable, net	672.1	722.2
Unbilled Receivables, Current	533.8	0.0
Inventory, net	929.5	1,449.9
Other current assets	30.0	53.5
Total current assets	2,603.7	2,651.1
Property, plant and equipment, net	2,105.4	2,105.3
Unbilled Receivable, Non Current	55.6	0.0
Pension assets	356.4	347.1
Other assets	249.2	164.3
Total assets	5,370.3	5,267.8
Liabilities
Accounts payable	819.6	693.1
Accrued expenses	330.4	269.3
Profit sharing	16.6	109.5
Current portion of long-term debt	31.2	31.1
Advance payments, short-term	103.3	100.0
Billings in Excess of Cost, Current	93.5	0.0
Provision for Loss on Contracts	165.7	0.0
Deferred revenue and other deferred credits, short-term	7.4	64.6
Deferred grant income liability - current	22.2	21.6
Other current liabilities	112.0	331.8
Total current liabilities	1,701.9	1,621.0
Liabilities Noncurrent
Long-term debt	1,112.6	1,119.9
Advance payments, long-term	203.1	231.7
Pension/OPEB obligation	40.0	40.8
Billings in Excess of Cost, Noncurrent	302.9	0.0
Provision for Loss on Contacts, Non Current	151.3	0.0
Deferred grant income liability - non-current	34.4	39.3
Deferred revenue and other deferred credits	31.7	161.0
Other liabilities	219.4	252.6
Stockholders' Equity Attributable to Parent [Abstract]
Preferred stock, par value $0.01, 10,000,000 shares authorized, no shares issued	0.0	0.0
Additional Paid in Capital [Abstract]
Additional paid-in capital	1,081.3	1,086.9
AccumulatedOtherComprehensiveIncomeLossNetOfTaxAbstract
Accumulated other comprehensive loss	(113.9)	(128.5)
Retained Earnings Accumulated Deficit [Abstract]
Retained earnings	2,260.0	2,422.4
Treasury Stock, Value	(1,656.0)	(1,580.9)
Total stockholders’ equity	1,572.5	1,801.0
Noncontrolling interest	0.5	0.5
Total equity	1,573.0	1,801.5
Total liabilities and equity	5,370.3	5,267.8
Class A [Member]
Stockholders' Equity Attributable to Parent [Abstract]
Common stock	$ 1.1	$ 1.1