Consolidated Balance Sheets (Unaudited) - USD ($) $ in Millions	Sep. 26, 2019	Dec. 31, 2018
Assets
Cash and cash equivalents	$ 1,477.3	$ 773.6
Restricted Cash, Current	0.3	0.3
Accounts receivable, net	708.6	545.1
Unbilled Receivables, Current	579.0	469.4
Inventory, net	1,015.2	1,012.6
Other current assets	58.3	48.3
Total current assets	3,838.7	2,849.3
Property, plant and equipment, net	2,199.8	2,167.6
Operating Lease, Right-of-Use Asset	49.7	0.0
Unbilled Receivable, Non Current	9.7	54.1
Pension assets	385.3	326.7
Other assets	218.4	288.2
Total assets	6,701.6	5,685.9
Liabilities
Accounts payable	1,140.5	902.6
Accrued expenses	319.8	313.1
Profit sharing	55.9	68.3
Current portion of long-term debt	37.6	31.4
Operating Lease, Liability, Current	6.2
Advance payments, short-term	19.8	2.2
Billings in Excess of Cost, Current	170.5	157.9
Provision for Loss on Contracts	37.2	12.4
Deferred revenue and other deferred credits, short-term	17.2	20.0
Deferred grant income liability - current	5.6	16.0
Other current liabilities	55.4	58.2
Total current liabilities	1,865.7	1,582.1
Liabilities Noncurrent
Long-term debt	2,132.2	1,864.0
Operating Lease, Liability, Noncurrent	43.6
Advance payments, long-term	335.1	231.9
Pension/OPEB obligation	32.6	34.6
Billings in Excess of Cost, Noncurrent	340.4	369.8
Provision for Loss on Contacts, Non Current	161.9	170.6
Deferred grant income liability - non-current	28.0	28.0
Deferred revenue and other deferred credits	32.4	31.2
Other liabilities	112.7	135.6
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	1,113.4	1,100.9
AccumulatedOtherComprehensiveIncomeLossNetOfTaxAbstract
Accumulated other comprehensive loss	(188.1)	(196.6)
Retained Earnings Accumulated Deficit [Abstract]
Retained earnings	3,146.2	2,713.2
Treasury Stock, Value	(2,456.0)	(2,381.0)
Total stockholders’ equity	1,616.5	1,237.6
Noncontrolling interest	0.5	0.5
Total equity	1,617.0	1,238.1
Total liabilities and equity	6,701.6	5,685.9
Class A [Member]
Stockholders' Equity Attributable to Parent [Abstract]
Common stock	$ 1.0	$ 1.1