Statement of Consolidated Cash Flows (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2014		Dec. 31, 2013		Dec. 31, 2012
Cash flows from operating activities:
Net income	$ 71.8		$ 104.8		$ 85.8
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation of property, plant and equipment	29.5		26.4		24.7
Amortization of definite-lived intangible assets	1.6		1.7		1.8
Amortization of debt discount and debt issuance costs	11.8		11.0		9.8
Deferred income taxes	34.3		55.4		52.0
Excess tax benefit upon vesting of non-vested shares and dividend payment on unvested shares expected to vest	(0.8)		(1.1)		(1.3)
Non-cash equity compensation	7.0		6.8		5.8
Non-cash unrealized losses (gains) on derivative instruments	6.8		(3.9)		(16.0)
Amortization of option premiums (received) paid, net	0		(0.1)		0.3
Non-cash impairment charges	1.5		0		4.4
Losses (gains) on disposition of property, plant and equipment	0.2		0.1		(0.1)
Losses (gains) on disposition of available for sale securities	0.1		(0.4)		0
Non-cash defined benefit net periodic benefit income	(23.5)		(22.0)		(11.5)
Other non-cash changes in assets and liabilities	0.6		(9.3)		1.2
Changes in operating assets and liabilities:
Trade and other receivables	(7.0)		(3.3)		(27.1)
Inventories	(0.3)		(28.4)		19.7
Prepaid expenses and other current assets1	(0.6)	[1]	1.1	[1]	1.4	[1]
Accounts payable	20.3		(1.6)		(1.3)
Accrued liabilities1	(6.0)	[1]	1.8	[1]	10.4	[1]
Other Postretirement Benefits Payments	(16.0)		(20.0)		0
Payable to affiliate	0		(7.9)		(6.5)
Long-term assets and liabilities, net1	(7.2)	[1]	0.6	[1]	(1.1)	[1]
Net cash provided by operating activities	124.1		111.7		152.4
Cash flows from investing activities:
Capital expenditures	(59.4)		(70.4)		(44.1)
Purchase of available for sale securities	(93.5)		(227.8)		(85.0)
Proceeds from disposition of available for sale securities	108.2		183.1		0
Proceeds from disposal of property, plant and equipment	0		0		0.3
Change in restricted cash	0		1.7		6.9
Net cash used in investing activities	(44.7)		(113.4)		(121.9)
Cash flows from financing activities:
Proceeds from issuance of Senior Notes	0	[2]	0	[2]	225.0	[2]
Payment of capital lease liability	(0.1)	[2]	(0.1)	[2]	(0.1)	[2]
Repayment of promissory notes	0	[2]	0	[2]	(4.7)	[2]
Cash paid for financing costs	0	[2]	0	[2]	(6.6)	[2]
Excess tax benefit upon vesting of non-vested shares and dividend payment on unvested shares expected to vest	0.8	[2]	1.1	[2]	1.3	[2]
Cancellation of shares to cover employees' tax withholdings upon vesting of non-vested shares	(2.4)	[2]	(2.5)	[2]	(2.2)	[2]
Repurchase of common stock	(44.1)	[2]	(78.3)	[2]	0	[2]
Cash dividend paid to stockholders	(25.4)	[2]	(23.0)	[2]	(19.6)	[2]
Cash dividend returned to the Company	0	[2]	0.6	[2]	0	[2]
Net cash (used in) provided by financing activities	(71.2)	[2]	(102.2)	[2]	193.1	[2]
Net increase (decrease) in cash and cash equivalents during the period	8.2		(103.9)		223.6
Cash and cash equivalents at beginning of period	169.5		273.4		49.8
Cash and cash equivalents at end of period	$ 177.7		$ 169.5		$ 273.4

[1] Excludes the reclassification of derivatives relating to the Company's cash convertible senior notes from long-term to current as the amounts have no impact on cash flow - see Note 3 and Note 11.

[2] See Note 14 for the supplemental disclosure on non-cash transactions.