Statement of Consolidated Cash Flows - USD ($) $ in Millions		6 Months Ended
		Jun. 30, 2016	Jun. 30, 2015
Cash flows from operating activities:
Net income		$ 52.3	$ (272.0)
Adjustments to reconcile net income (loss) to net cash provided by operating activities:
Depreciation of property, plant and equipment		16.9	15.3
Amortization of definite-lived intangible assets		0.8	0.8
Amortization of debt discount and debt issuance costs		0.5	3.6
Deferred income taxes		31.3	(163.8)
Excess tax benefit upon vesting of non-vested shares and dividend payment on unvested shares expected to vest1	[1]	0.0	(1.1)
Non-cash equity compensation	[2]	5.7	4.8
Lower of cost or market inventory write-down		4.9	0.0
Loss on extinguishment of debt		11.1	0.0
Non-cash unrealized (gain) loss on derivative instruments		(14.9)	6.0
Non-cash defined benefit net periodic benefit cost relating to Salaried VEBA		1.7	1.2
Non-cash loss on removal of Union VEBA net assets	[3]	0.0	446.7
Other non-cash changes in assets and liabilities		0.9	0.4
Changes in operating assets and liabilities:
Trade and other receivables		(20.0)	(4.3)
Inventories, excluding lower of cost or market write-down		(2.8)	(2.6)
Prepaid expenses and other current assets		(2.7)	(1.7)
Accounts payable		3.4	(6.1)
Accrued liabilities	[3]	17.4	7.0
Annual variable cash contributions to VEBAs	[3]	(19.5)	(13.7)
Long-term assets and liabilities, net	[3]	(14.9)	27.8
Net cash provided by operating activities		72.1	48.3
Cash flows from investing activities
Capital expenditures		(42.3)	(22.9)
Purchase of available for sale securities		(72.4)	(0.5)
Proceeds from disposition of available for sale securities		30.0	84.0
Net cash (used in) provided by investing activities	[4]	(84.7)	60.6
Cash flows from financing activities
Repayment of principal and redemption premium of 8.25% Senior Notes		(206.0)	0.0
Issuance of 5.875% Senior Notes		375.0	0.0
Cash paid for debt issuance costs		(6.9)	0.0
Repayment of Convertible Notes		0.0	(175.0)
Proceeds from cash-settled call options related to repayment of Convertible Notes		0.0	94.9
Payment for conversion premium related to repayment of Convertible Notes		0.0	(94.9)
Proceeds from stock option exercises		1.0	0.0
Repayment of capital lease		(0.1)	0.0
Excess tax benefit upon vesting of non-vested shares and dividend payment on unvested shares expected to vest	[2]	0.0	1.1
Cancellation of shares to cover employees' tax withholdings upon vesting of non-vested shares		(2.8)	(3.0)
Repurchase of common stock		(8.5)	(41.4)
Cash dividends paid to stockholders		(16.3)	(14.0)
Net cash provided by (used in) financing activities	[4]	135.4	(232.3)
Net increase (decrease) in cash and cash equivalents during the period		122.8	(123.4)
Cash and cash equivalents at beginning of period		72.5	177.7
Cash and cash equivalents at end of period		$ 195.3	$ 54.3

[1] See Note 4 and Note 6 for discussion of our adoption of ASU 2016-09.

[2] See Note 4 and Note 6 for discussion of our adoption of ASU 2016-09 (as defined in Note 1).

[3] See Note 5 for the impact of removing the Union VEBA (defined in Note 5) net assets.

[4] See Note 12 for the supplemental disclosure on non-cash transactions.