Condensed Consolidated Balance Sheets - USD ($) $ in Millions	Mar. 31, 2017	Dec. 31, 2016
Current Assets
Cash and cash equivalents	$ 382.1	$ 410.3
Accounts receivable	202.2	136.4
Inventories	160.4	185.1
Recoverable from the U.S. government and other third parties for environmental remediation costs	23.2	25.2
Receivable from Northrop Grumman Corporation (“Northrop”)	6.0	6.0
Other current assets, net	96.4	91.7
Total Current Assets	870.3	854.7
Noncurrent Assets
Property, plant and equipment, net	361.4	366.0
Real estate held for entitlement and leasing	92.3	91.8
Recoverable from the U.S. government and other third parties for environmental remediation costs	237.7	239.8
Receivable from Northrop	61.7	62.0
Deferred income taxes	284.3	292.5
Goodwill	159.9	158.1
Intangible assets	95.5	94.4
Other noncurrent assets, net	92.1	90.2
Total Noncurrent Assets	1,384.9	1,394.8
Total Assets	2,255.2	2,249.5
Current Liabilities
Current portion of long-term debt	19.9	55.6
Accounts payable	98.2	96.2
Reserves for environmental remediation costs	36.0	37.1
Postretirement medical and life insurance benefits	5.2	5.2
Advance payments on contracts	208.6	221.8
Other current liabilities	181.7	167.8
Total Current Liabilities	549.6	583.7
Noncurrent Liabilities
Long-term debt	604.9	608.0
Reserves for environmental remediation costs	309.5	312.6
Pension benefits	540.8	548.2
Postretirement medical and life insurance benefits	36.7	37.4
Other noncurrent liabilities	124.8	124.0
Total Noncurrent Liabilities	1,616.7	1,630.2
Total Liabilities	2,166.3	2,213.9
Commitments and contingencies (Note 8)
Redeemable common stock, par value of $0.10; less than 0.1 million shares issued and outstanding as of March 31, 2017; 0.1 million shares issued and outstanding as of December 31, 2016	0.1	1.1
Stockholders’ Equity
Preference stock, par value of $1.00; 15.0 million shares authorized; none issued or outstanding	0.0	0.0
Common stock, par value of $0.10; 150.0 million shares authorized; 73.5 million shares issued and outstanding as of March 31, 2017; 69.2 million shares issued and outstanding as of December 31, 2016	7.3	6.9
Other capital	495.2	456.9
Treasury stock at cost, 3.5 million shares as of March 31, 2017 and December 31, 2016	(64.5)	(64.5)
Accumulated deficit	(55.9)	(61.8)
Accumulated other comprehensive loss, net of income taxes	(293.3)	(303.0)
Total Stockholders’ Equity	88.8	34.5
Total Liabilities, Redeemable Common Stock and Stockholders’ Equity	$ 2,255.2	$ 2,249.5