Consolidated Balance Sheets (USD $) In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Current assets:
Cash and cash equivalents	$ 70.9	$ 65.5
Accounts receivable, net	233.5	232.4
Inventories	290.1	265.3
Prepaid expenses and other current assets	87.2	93.2
Total current assets	681.7	656.4
Property, plant and equipment, net	1,238.2	1,067.4
Goodwill and other intangible assets	59.8	61.0
Investments in affiliated companies	34.2	23.3
Other assets	22.5	28.0
Total assets	2,036.4	1,836.1
Current liabilities:
Short-term borrowings and current maturities of long-term debt	1.3	3.0
Accounts payable	175.0	135.9
Accrued compensation and benefits	66.4	89.2
Other accrued liabilities	67.9	40.6
Total current liabilities	310.6	268.7
Long-term notes payable and capital lease obligations	415.0	292.0
Long-term retirement obligations	38.7	41.1
Other non-current liabilities	122.2	73.9
Total liabilities	886.5	675.7
Commitments and contingencies (see Note 13)
Stockholders’ equity:
Common stock, $0.01 par value, 200.0 shares of stock authorized, 104.8 and 104.0 shares of stock issued at December 31, 2014 and 2013, respectively	1.0	1.0
Additional paid-in capital	678.5	642.3
Retained earnings	845.5	636.1
Accumulated other comprehensive (loss) income	(69.7)	10.7
Total stockholders' equity including treasury stock value	1,455.3	1,290.1
Less: Treasury stock, at cost, 9.3 and 5.1 shares at December 31, 2014 and 2013, respectively	(305.4)	(129.7)
Total stockholders’ equity	1,149.9	1,160.4
Total liabilities and stockholders’ equity	$ 2,036.4	$ 1,836.1