CONSOLIDATED BALANCE SHEETS (UNAUDITED) - USD ($) $ in Millions	Sep. 30, 2020	Dec. 31, 2019
Current assets:
Cash and cash equivalents	$ 750.1	$ 264.3
Short-term investments		78.7
Receivables:
Trade receivables, net	119.0	167.1
Other	22.8	18.1
Contract assets	34.8	54.6
Inventories	157.5	177.6
Prepaid expenses and other current assets	25.4	19.4
Total current assets	1,109.6	779.8
Property, plant and equipment, net	622.9	622.0
Operating lease assets	27.2	25.8
Deferred tax assets, net		11.8
Intangible assets, net	27.4	29.6
Goodwill	18.8	18.8
Other assets	41.1	38.4
Total	1,847.0	1,526.2
Current liabilities:
Accounts payable	63.4	92.0
Accrued salaries, wages and related expenses	33.5	34.4
Other accrued liabilities	45.3	44.0
Total current liabilities	142.2	170.4
Long-term portion of operating lease liabilities	26.3	25.2
Net liabilities of Salaried VEBA	32.4	32.6
Deferred tax liabilities	8.9	4.5
Long-term liabilities	80.3	67.0
Long-term debt	837.6	492.6
Total liabilities	1,127.7	792.3
Commitments and contingencies
Stockholders’ equity:
Preferred stock, 5,000,000 shares authorized at both September 30, 2020 and December 31, 2019; no shares were issued and outstanding at September 30, 2020 and December 31, 2019
Common stock, par value $0.01, 90,000,000 shares authorized at both September 30, 2020 and at December 31, 2019; 22,647,455 shares issued and 15,812,169 shares outstanding at September 30, 2020; 22,550,827 shares issued and 15,868,304 shares outstanding at December 31, 2019	0.2	0.2
Additional paid in capital	1,066.0	1,062.9
Retained earnings	163.0	172.8
Treasury stock, at cost, 6,835,286 shares at September 30, 2020 and 6,682,523 shares at December 31, 2019, respectively	(475.9)	(463.4)
Accumulated other comprehensive loss	(34.0)	(38.6)
Total stockholders’ equity	719.3	733.9
Total	$ 1,847.0	$ 1,526.2