Summary of Significant Accounting Policies (Tables)

12 Months Ended

Dec. 31, 2016

Change in Accounting Estimate [Line Items]

Schedule of Fair Value of Financial Instruments

The following are measured at fair value:

			Fair value measurement at December 31, 2016
	Total		Quoted Prices in Active Markets for Identical Assets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)
	(In millions)
Money market funds	$	328.5	$	328.5	$	—	$	—
			Fair value measurement at December 31, 2015
	Total		Quoted Prices in Active Markets for Identical Assets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)
	(In millions)
Money market funds	$	141.8	$	141.8	$	—	$	—

Summary of Cash and Cash Equivalents and Grantor Trust by Investment Type

As of December 31, 2016, a summary of cash and cash equivalents and the grantor trust by investment type was as follows:

	Total		Cash and Cash Equivalents		Money Market Funds
	(In millions)
Cash and cash equivalents	$	410.3	$	89.8	$	320.5
Grantor trust (included as a component of other current and noncurrent assets)	8.0		—		8.0
	$	418.3	$	89.8	$	328.5

Schedule of Estimated Fair Value and Principal Amount of Outstanding Debt

The following table summarizes the estimated fair value and principal amount for outstanding debt obligations:

	Fair Value				Principal Amount
	December 31, 2016		December 31, 2015		December 31, 2016		December 31, 2015
	(In millions)
Term loan	$	390.0	$	92.5	$	390.0	$	92.5
7.125% Second-Priority Senior Secured Notes (“7 1/8% Notes”)	—		479.6		—		460.0
2.25% Convertible Senior Notes ("2 1/4% Notes")	294.9		—		300.0		—
4 1/16% Convertible Subordinated Debentures (“4 1/16% Debentures”) (1)	70.8		149.5		35.6		84.6
Delayed draw term loan	—		13.0		—		13.0
Other debt	—		0.6		—		0.5
	$	755.7	$	735.2	$	725.6	$	650.6

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(1) In December 2016, the Company notified holders of its 4 ¹/₁₆% Debentures that the Company would redeem, on February 3, 2017, all of their 4 ¹/₁₆% Debentures at a purchase price equal to 100% of the principal amount of the 4 ¹/₁₆% Debentures to be redeemed, plus any accrued and unpaid interest. In January 2017, $35.6 million of the 4 ¹/₁₆% Debentures (the entire amount outstanding as of December 31, 2016) were converted to 3.9 million shares of common stock.

Schedule of Useful Lives of Property, Plant and Equipment

Depreciation is computed principally by accelerated methods based on the following useful lives:

Buildings and improvements	9 - 40  years
Machinery and equipment	5 - 19  years

Schedule of Changes in Carrying Amount of Conditional Asset Retirement Obligations

The changes in the carrying amount of CAROs since November 30, 2013 were as follows (in millions):

Balance as of November 30, 2013	$	22.9
Additions and other, net	(0.2		)
Accretion	1.7
Balance as of November 30, 2014	24.4
Additions and other, net	3.0
Accretion	1.9
Balance as of November 30, 2015	29.3
Accretion	0.2
Balance as of December 31, 2015	29.5
Additions and other, net	(0.9		)
Accretion	2.0
Balance as of December 31, 2016	$	30.6

AR1 Inception to Date Project Costs

The AR1 inception to date project costs were as follows (in millions):

AR1 R&D costs incurred	$	169.3
Less amounts funded by the U.S. Air Force	(92.9		)
Less amounts funded by ULA	(5.0		)
AR1 R&D costs net of reimbursements	71.4
AR1 R&D costs expensed and not applied to contracts	(32.1		)
Net AR1 R&D costs applied to contracts	$	39.3

Schedule of Sales to U.S. Government and its Agencies

Sales to the U.S. government and its agencies, including sales to the Company’s significant customers discussed below, were as follows:

	Percentage of Net Sales
Fiscal 2016	91	%
Fiscal 2015	90	%
Fiscal 2014	92	%
One month ended December 31, 2015	85	%

Schedule of Customers that Represented More than 10% of Net Sales

Customers that represented more than 10% of net sales for the periods presented were as follows:

	Year Ended						One month ended
	December 31,		November 30,		November 30,		December 31,
	2016		2015		2014		2015
Lockheed Martin Corporation ("Lockheed Martin")	27	%	29	%	28	%	24	%
ULA	21		19		25		28
Raytheon Company ("Raytheon")	20		20		17		19
NASA	13		11		11		10

Schedule of Customers that Represented More than 10% of Accounts Receivable

Customers that represented more than 10% of accounts receivable for the periods presented were as follows:

	As of December 31,
	2016		2015
ULA	20	%	14	%
Lockheed Martin	17		16
Raytheon	17		19
NASA	14		*
The Boeing Company ("Boeing")	13		24

_____

* Less than 10%

Contracts Accounted for under Percentage-of-Completion [Member]

Change in Accounting Estimate [Line Items]

Summary of Impact of Contracts in Progress on Statement of Operations

The following table summarizes the impact from changes in estimates and assumptions on the statements of operations on contracts, representing 94% of the Company’s aerospace and defense segment net sales over the last three fiscal years and one month ended December 31, 2015, accounted for under the percentage-of-completion method of accounting:

	Year Ended						One month ended
	December 31,		November 30,		November 30,		December 31,
	2016		2015		2014		2015
	(In millions, except per share amounts)
Favorable effect of the changes in contract estimates on income (loss) from continuing operations before income taxes	$	14.1	$	41.2	$	9.2	$	11.7
Favorable effect of the changes in contract estimates on net income (loss)	8.5		24.7		5.5		7.0
Favorable effect of the changes in contract estimates on basic net income (loss) per share	0.13		0.40		0.10		0.11
Favorable effect of the changes in contract estimates on diluted net income (loss) per share	0.11		0.40		0.10		0.09