Condensed Consolidated Statements of Cash Flows - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Operating Activities
Net income	$ 5.9	$ 5.1
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	16.3	15.1
Amortization of debt discount and deferred financing costs	2.1	0.6
Stock-based compensation	6.8	2.3
Retirement benefits, net	7.7	8.5
Loss on debt	0.0	0.3
Loss on disposal of long-lived assets	0.1	0.0
Changes in assets and liabilities, net of effects from acquisition:
Accounts receivable	(54.3)	(12.8)
Inventories	24.7	(14.4)
Other current assets, net	(4.4)	(1.6)
Real estate held for entitlement and leasing	(0.6)	(1.2)
Receivable from Northrop	0.3	0.5
Recoverable from the U.S. government and other third parties for environmental remediation costs	4.1	2.2
Other noncurrent assets	(3.1)	2.8
Accounts payable	1.1	22.5
Advance payments on contracts	(13.2)	(30.1)
Other current liabilities	4.9	(23.3)
Deferred income taxes	2.3	(3.8)
Reserves for environmental remediation costs	(4.2)	(3.0)
Other noncurrent liabilities and other	0.4	(1.4)
Net Cash Used in Operating Activities	(3.1)	(31.7)
Investing Activities
Purchase of Coleman Aerospace (see Note 5)	15.0	0.0
Capital expenditures	(2.7)	(7.7)
Net Cash Used in Investing Activities	(17.7)	(7.7)
Financing Activities
Debt repayments	(5.0)	(14.4)
Repurchase of shares for withholding taxes and option costs under employee equity plans	(4.7)	(0.7)
Proceeds from shares issued under equity plans	2.3	1.5
Net Cash Used in Financing Activities	(7.4)	(13.6)
Net Decrease in Cash and Cash Equivalents	(28.2)	(53.0)
Cash and Cash Equivalents at Beginning of Period	410.3	208.5
Cash and Cash Equivalents at End of Period	382.1	155.5
Supplemental disclosures of cash flow information
Cash paid for interest	4.0	17.7
Cash paid for income taxes	0.0	12.7
Conversion of debt to common stock	$ 35.6	$ 0.0