Statement of Consolidated Cash Flows (USD $) In Millions, unless otherwise specified	6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012
Cash flows from operating activities:
Net income	$ 52.1	$ 47.5
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation of property, plant and equipment	13.1	12.0
Amortization of definite-lived intangible assets	0.9	0.9
Amortization of debt discount and debt issuance costs	5.4	4.6
Deferred income taxes	26.1	28.9
Excess tax benefit upon vesting of non-vested shares and dividend payment on unvested shares expected to vest	(0.9)	(1.3)
Non-cash equity compensation	4.7	3.8
Net non-cash LIFO benefit	(12.9)	(7.8)
Non-cash unrealized losses (gains) on derivative positions	5.4	(4.2)
Amortization of option premiums paid	0	0.2
Losses on disposition of property, plant and equipment	0.1	0
Gain on sale of available for sale securities	(0.3)	0
Non-cash net periodic pension benefit income relating to VEBAs	(11.3)	(6.0)
Other non-cash (benefit) charges	(2.5)	0.7
Changes in operating assets and liabilities:
Trade and other receivables	(4.5)	(33.1)
Inventories (excluding LIFO benefit/charge)	(4.0)	16.7
Prepaid expenses and other current assets	(1.7)	(1.4)
Accounts payable	9.1	4.0
Accrued liabilities	(20.2)	7.1
Payable to affiliate	(7.9)	3.9
Long-term assets and liabilities, net	(1.8)	(1.8)
Net cash provided by operating activities	48.9	74.7
Cash flows from investing activities:
Capital expenditures	(26.0)	(16.9)
Purchase of available for sale securities	(98.2)	(0.3)
Proceeds from sale of available for sale securities	135.7	0
Change in restricted cash	0.7	7.2
Net cash provided by (used in) investing activities	12.2	(10.0)
Cash flows from financing activities:
Proceeds from issuance of senior notes	0	225.0
Cash paid for financing costs	0	(6.4)
Repayment of promissory notes	0	(4.7)
Excess tax benefit upon vesting of non-vested shares and dividend payment on unvested shares expected to vest	0.9	1.3
Cancellation of shares to cover employees’ tax withholdings upon vesting of non-vested shares	(2.2)	(2.1)
Repurchase of common stock	(39.9)	0
Cash dividend paid to stockholders	(11.6)	(9.8)
Net cash (used in) provided by financing activities	(52.8)	203.3
Net increase in cash and cash equivalents during the period	8.3	268.0
Cash and cash equivalents at beginning of period	273.4	49.8
Cash and cash equivalents at end of period	$ 281.7	$ 317.8