Condensed Consolidated Balance Sheets - USD ($) $ in Millions	Jun. 30, 2020	Dec. 31, 2019
Current Assets
Cash and cash equivalents	$ 1,003.9	$ 932.6
Restricted cash	3.0	3.0
Marketable securities	25.0	0.0
Accounts receivable, net	80.4	112.5
Contract assets	287.9	224.1
Other current assets, net	114.2	145.8
Total Current Assets	1,514.4	1,418.0
Noncurrent Assets
Right-of-use assets	51.8	48.0
Property, plant and equipment, net	401.5	409.9
Recoverable environmental remediation costs	224.5	234.8
Deferred income taxes	111.2	121.9
Goodwill	161.4	161.4
Intangible assets	51.3	58.2
Other noncurrent assets, net	248.1	255.6
Total Noncurrent Assets	1,249.8	1,289.8
Total Assets	2,764.2	2,707.8
Current Liabilities
Current portion of long-term debt	293.2	284.7
Accounts payable	82.3	127.3
Reserves for environmental remediation costs	42.4	40.1
Contract liabilities	295.7	262.3
Other current liabilities	147.7	155.5
Total Current Liabilities	861.3	869.9
Noncurrent Liabilities
Long-term debt	338.4	352.3
Reserves for environmental remediation costs	256.9	269.1
Pension benefits	389.6	398.9
Operating lease liabilities	41.3	39.1
Other noncurrent liabilities	205.4	201.8
Total Noncurrent Liabilities	1,231.6	1,261.2
Total Liabilities	2,092.9	2,131.1
Commitments and contingencies (Note 8)
Stockholders’ Equity
Preferred 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; 77.6 million shares issued and outstanding as of June 30, 2020; 77.3 million shares issued and outstanding as of December 31, 2019	7.7	7.7
Other capital	577.6	573.3
Treasury stock at cost, 0.8 million shares as of June 30, 2020 and December 31, 2019	(13.2)	(12.7)
Retained earnings	315.5	244.9
Accumulated other comprehensive loss, net of income taxes	(216.3)	(236.5)
Total Stockholders’ Equity	671.3	576.7
Total Liabilities and Stockholders’ Equity	$ 2,764.2	$ 2,707.8