Consolidated Statements of Cash Flows - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Operating activities
Net income (loss)	$ 788.7	$ 358.8	$ (621.4)
Adjustments to reconcile net income (loss) to net cash provided by operating activities
Depreciation expense	180.5	170.2	158.2
Amortization expense	0.6	5.8	3.1
Amortization of deferred financing fees	6.9	23.3	6.7
Accretion of customer supply agreement	2.6	1.1	0.6
Employee stock compensation expense	26.0	16.4	19.6
Excess tax benefit of share-based payment arrangements	(10.7)	(2.6)	(0.6)
Loss from interest rate swaps	0.0	0.5	0.0
Loss (gain) from hedge contracts	1.6	(1.4)	(2.6)
Loss (gain) from foreign currency transactions	8.6	10.5	(2.6)
Loss on sale of divestiture of programs - cash flow	0.0	471.1	0.0
Loss on disposition of assets	14.7	13.7	0.1
Deferred taxes	(162.2)	(8.4)	202.8
Long-term tax benefit	0.0	(1.2)	(2.5)
Pension and other post retirement benefits, net	(26.0)	(24.0)	(32.0)
Grant income	(10.4)	(8.6)	(7.3)
Equity in net income of affiliates	(1.2)	(0.5)	(0.5)
Changes in assets and liabilities
Accounts receivable, net	62.2	(64.7)	(128.5)
Inventory, net	(44.2)	(332.2)	666.0
Accounts payable and accrued liabilities	(89.1)	(22.1)	94.2
Profit sharing/deferred compensation	(50.0)	73.8	10.0
Advance payments	(113.3)	(52.9)	(41.9)
Income taxes receivable/payable	251.9	(177.9)	(82.2)
Deferred revenue and other deferred credits	407.3	2.2	(0.2)
Proceeds from Divestiture of Businesses, Net of Cash Divested	0.0	(160.0)	0.0
Other	45.2	70.7	21.6
Net cash provided by operating activities	1,289.7	361.6	260.6
Investing activities
Purchase of property, plant and equipment	(360.1)	(220.2)	(234.2)
Purchase of property, plant and equipment — severe weather event	0.0	0.0	(38.4)
Proceeds from sale of assets	2.7	0.5	0.7
Repayments of Notes Payable	0.0	(300.0)	0.0
Increase (Decrease) in Restricted Cash	0.0	(19.9)	0.0
Payments for (Proceeds from) Other Investing Activities	0.0	0.0	(3.7)
Net cash used in investing activities	(357.4)	(239.6)	(268.2)
Payments Related to Tax Withholding for Share-based Compensation	(20.7)	0.0	0.0
Financing activities
Proceeds from issuance of debt	535.0	0.0	0.0
Principal payments of debt	36.5	16.8	10.4
Excess tax benefit of share-based payment arrangements	10.7	2.6	0.6
Debt issuance and financing costs	4.7	20.8	4.1
Payments for Repurchase of Common Stock	(300.0)	(129.2)	0.0
Net cash used in financing activities	(351.1)	(164.2)	(13.9)
Repayments of Debt	(534.9)	0.0	0.0
Proceeds from (Repayments of) Notes Payable	0.0	300.0	0.0
Effect of exchange rate changes on cash and cash equivalents	(1.8)	(0.6)	1.5
Net increase (decrease) in cash and cash equivalents for the period	579.4	(42.8)	(20.0)
Cash and cash equivalents, beginning of period	377.9	420.7	440.7
Cash and cash equivalents, end of period	957.3	377.9	420.7
Supplemental information
Interest paid	51.5	69.2	68.0
Proceeds from Income Tax Refunds	$ (69.7)
Income taxes paid		$ 91.1	$ 69.4