Consolidated Balance Sheets - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020
Current Assets
Cash and cash equivalents	$ 700.4	$ 1,149.5
Restricted cash	3.0	3.0
Marketable securities	10.6	7.0
Accounts receivable	60.6	75.6
Contract assets	354.2	288.6
Other current assets	107.8	136.5
Total Current Assets	1,236.6	1,660.2
Noncurrent Assets
Right-of-use assets	52.6	46.8
Property, plant and equipment, net	421.1	423.1
Recoverable environmental remediation costs	226.2	227.7
Deferred income taxes	57.5	81.1
Goodwill	161.4	161.4
Intangible assets	34.9	44.8
Other noncurrent assets	243.3	254.8
Total Noncurrent Assets	1,197.0	1,239.7
Total Assets	2,433.6	2,899.9
Current Liabilities
Current portion of long-term debt	166.7	299.9
Accounts payable	132.2	99.1
Reserves for environmental remediation costs	37.7	39.8
Contract liabilities	366.5	407.2
Other current liabilities	172.7	609.7
Total Current Liabilities	875.8	1,455.7
Noncurrent Liabilities
Long-term debt	294.6	324.4
Reserves for environmental remediation costs	258.7	260.8
Pension benefits	255.9	405.2
Operating lease liabilities	41.3	35.7
Other noncurrent liabilities	173.8	184.6
Total Noncurrent Liabilities	1,024.3	1,210.7
Total Liabilities	1,900.1	2,666.4
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; 80.1 million shares issued and outstanding as of December 31, 2021; 76.8 million shares issued and outstanding as of December 31, 2020	8.0	7.7
Other capital	599.0	583.0
Treasury stock at cost, 2.1 million at December 31, 2021 and 2020	(64.4)	(64.4)
Retained earnings (accumulated deficit)	91.9	(65.2)
Accumulated other comprehensive loss, net of income taxes	(101.0)	(227.6)
Total Stockholders’ Equity	533.5	233.5
Total Liabilities and Stockholders’ Equity	$ 2,433.6	$ 2,899.9