Income Taxes Effective tax rate (Details 2) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
The components of earnings from consolidated companies before income taxes, and the effects of significant adjustments to tax computed at the federal statutory rate, were as follows:
United States earnings (loss)	$ (96.4)	$ 676.0	$ 312.9
Non-U.S. earnings	338.8	427.3	904.4
Earnings from consolidated companies before income taxes	$ 242.4	$ 1,103.3	$ 1,217.3
Effective Income Tax Rate Continuing Operations Tax Rate Reconciliation
Computed tax at the U.S. federal statutory rate of 35%	35.00%	35.00%	35.00%
State and local income taxes, net of federal income tax benefit	(6.10%)	(0.50%)	0.10%
Percentage depletion in excess of basis	(34.40%)	(11.00%)	(9.70%)
Impact of non-U.S. earnings	(4.00%)	(13.60%)	(3.80%)
Non-taxable change in value of share repurchase agreement	0.00%	0.00%	1.70%
Change in valuation allowance	7.70%	(0.10%)	(7.60%)
Resolution of uncertain tax positions	(34.90%)	0.00%	0.00%
Share-based excess cost/(benefits)	2.20%	0.00%	0.00%
Other items (none in excess of 5% of computed tax)	3.90%	(0.80%)	(0.50%)
Effective tax rate	(30.60%)	9.00%	15.20%
Effective Income Tax Rate Reconciliation, Amounts
Effective Income Tax Rate Reconciliation, Other Adjustments, Amount	$ (54.2)	$ (28.2)	$ (47.0)
Effective income tax rate reconciliation, resolution of Advanced Pricing Agreement, amount	(85.8)	(14.5)
Effective Income Tax Rate Reconciliation, Disposition of Business, Amount		(6.2)	53.6
Effective Income Tax Rate Reconciliation, Change in Enacted Tax Rate, Amount		(7.5)
Effective Income Tax Rate Reconciliation, Tax Contingency, State and Local, Amount		$ (18.4)
Effective Income Tax Rate Reconciliation, Repatriation of Foreign Earnings, Amount	23.3		81.0
Effective Income Tax Rate Reconciliation, Nondeductible Expense, Share-based Compensation Cost, Amount	$ 8.3
Effective Income Tax Rate Reconciliation, Tax Settlement, Foreign, Amount			(8.1)
Effective Income Tax Rate Reconciliation, Change in Deferred Tax Assets Valuation Allowance, Amount			$ 32.8