Consolidated Balance Sheets - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Current Assets
Cash and cash equivalents	$ 1,149.5	$ 932.6
Restricted cash	3.0	3.0
Marketable securities	7.0	0.0
Accounts receivable, net	75.6	112.5
Contract assets	288.6	224.1
Other current assets, net	136.5	145.8
Total Current Assets	1,660.2	1,418.0
Noncurrent Assets
Right-of-use assets	46.8	48.0
Property, plant and equipment, net	423.1	409.9
Recoverable environmental remediation costs	227.7	234.8
Deferred income taxes	81.1	121.9
Goodwill	161.4	161.4
Intangible assets	44.8	58.2
Other noncurrent assets, net	254.8	255.6
Total Noncurrent Assets	1,239.7	1,289.8
Total Assets	2,899.9	2,707.8
Current Liabilities
Current portion of long-term debt	299.9	284.7
Accounts payable	99.1	127.3
Reserves for environmental remediation costs	39.8	40.1
Contract liabilities	407.2	262.3
Dividends payable	447.8	0.0
Other current liabilities	161.9	155.5
Total Current Liabilities	1,455.7	869.9
Noncurrent Liabilities
Long-term debt	324.4	352.3
Reserves for environmental remediation costs	260.8	269.1
Pension benefits	405.2	398.9
Operating lease liabilities	35.7	39.1
Other noncurrent liabilities	184.6	201.8
Total Noncurrent Liabilities	1,210.7	1,261.2
Total Liabilities	2,666.4	2,131.1
Commitments and contingencies
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; 76.8 million shares issued and outstanding as of December 31, 2020; 77.3 million shares issued and outstanding as of December 31, 2019	7.7	7.7
Other capital	583.0	573.3
Treasury stock at cost, 2.1 million at December 31, 2020; 0.8 million shares as of December 31, 2019	(64.4)	(12.7)
(Accumulated deficit) retained earnings	(65.2)	244.9
Accumulated other comprehensive loss, net of income taxes	(227.6)	(236.5)
Total Stockholders’ Equity	233.5	576.7
Total Liabilities and Stockholders’ Equity	$ 2,899.9	$ 2,707.8