Condensed Consolidated Balance Sheets - USD ($) $ in Millions	Sep. 30, 2020	Dec. 31, 2019
Current Assets
Cash and cash equivalents	$ 1,010.0	$ 932.6
Restricted cash	3.0	3.0
Marketable securities	1.5	0.0
Accounts receivable, net	182.4	112.5
Contract assets	273.3	224.1
Other current assets, net	138.5	145.8
Total Current Assets	1,608.7	1,418.0
Noncurrent Assets
Right-of-use assets	48.9	48.0
Property, plant and equipment, net	403.8	409.9
Recoverable environmental remediation costs	228.8	234.8
Deferred income taxes	107.8	121.9
Goodwill	161.4	161.4
Intangible assets	48.0	58.2
Other noncurrent assets, net	247.4	255.6
Total Noncurrent Assets	1,246.1	1,289.8
Total Assets	2,854.8	2,707.8
Current Liabilities
Current portion of long-term debt	297.7	284.7
Accounts payable	93.7	127.3
Reserves for environmental remediation costs	42.1	40.1
Contract liabilities	343.4	262.3
Other current liabilities	144.2	155.5
Total Current Liabilities	921.1	869.9
Noncurrent Liabilities
Long-term debt	331.4	352.3
Reserves for environmental remediation costs	262.0	269.1
Pension benefits	379.9	398.9
Operating lease liabilities	38.3	39.1
Other noncurrent liabilities	213.2	201.8
Total Noncurrent Liabilities	1,224.8	1,261.2
Total Liabilities	2,145.9	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; 77.4 million shares issued and outstanding as of September 30, 2020; 77.3 million shares issued and outstanding as of December 31, 2019	7.7	7.7
Other capital	585.2	573.3
Treasury stock at cost, 1.1 million shares as of September 30, 2020; 0.8 million shares as of December 31, 2019	(25.0)	(12.7)
Retained earnings	347.2	244.9
Accumulated other comprehensive loss, net of income taxes	(206.2)	(236.5)
Total Stockholders’ Equity	708.9	576.7
Total Liabilities and Stockholders’ Equity	$ 2,854.8	$ 2,707.8