Condensed Consolidated Balance Sheets - USD ($) $ in Millions	Jun. 30, 2019	Dec. 31, 2018
Current assets:
Cash and cash equivalents	$ 55.4	$ 32.7
Accounts receivable, net	313.3	260.9
Inventories, net	339.3	297.8
Contract assets	59.7	50.5
Prepaid expenses and other current assets	30.4	33.9
Total current assets	798.1	675.8
Property, plant and equipment	3,005.3	2,902.1
Less accumulated depreciation	(1,083.4)	(1,025.6)
Net property, plant and equipment	1,921.9	1,876.5
Goodwill and other intangible assets	283.6	142.3
Investments in affiliated companies	51.8	48.7
Other assets	139.7	80.8
Total assets	3,195.1	2,824.1
Current liabilities:
Short-term borrowings	9.7	9.4
Accounts payable	177.8	161.9
Accrued compensation and benefits	66.9	75.8
Accrued liabilities	105.3	79.6
Total current liabilities	359.7	326.7
Commitments and contingencies (see Note 14)
Long-term debt	1,115.8	947.4
Retirement obligations	42.4	42.0
Other non-current liabilities	234.8	186.0
Total liabilities	1,752.7	1,502.1
Stockholders' equity:
Common stock, $0.01 par value, 200.0 shares authorized, 109.0 shares and 108.5 shares issued at June 30, 2019 and December 31, 2018, respectively	1.1	1.1
Additional paid-in capital	817.9	798.3
Retained earnings	1,854.1	1,726.5
Accumulated other comprehensive loss	(118.1)	(108.0)
Total stockholders' equity including treasury stock value	2,555.0	2,417.9
Less – Treasury stock, at cost, 24.0 shares at June 30, 2019, and 23.7 shares at December 31, 2018, respectively.	(1,112.6)	(1,095.9)
Total stockholders' equity	1,442.4	1,322.0
Total liabilities and stockholders' equity	$ 3,195.1	$ 2,824.1