Income Taxes (Details Textuals) (USD $)	3 Months Ended		12 Months Ended
	Dec. 31, 2012	Jun. 30, 2012	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Income Taxes (Textuals) [Abstract]
Alternative minimum tax credits	$ 232,600,000			$ 232,600,000
General business credits	52,600,000			52,600,000
Capital loss	113,200,000			113,200,000
Deferred tax assets, operating loss carryforwards	36,100,000			36,100,000
Foreign loss carryforwards included in Company's tax credits and loss carryforwards	955,600,000			955,600,000
Change in valuation allowance				521,500,000
Valuation allowance reserve for U.S. capital losses, state NOLs, foreign NOLs and certain foreign deferred tax assets	714,900,000			714,900,000	79,800,000
Minerals resource rent tax percentage	22.50%			22.50%
Minerals resource rent tax deferred liability	(77,200,000)			(77,200,000)	0	0
MRRT market value allowance deferred tax asset	871,800,000			871,800,000
Excess book over tax basis on exploration properties	182,100,000			182,100,000
Valuation allowance minerals resource rent tax	766,900,000			766,900,000
Net tax benefits related to acquisition restructuring	15,000,000	59,700,000		74,700,000
Federal and state capital loss tax benefit				39,600,000
Foreign tax benefit due to restructuring				35,100,000
Net unrecognized tax benefits included in other noncurrent liabilities	119,700,000			119,700,000	114,700,000
Gross unrecognized tax benefits included in other noncurrent liabilities	122,800,000			122,800,000	119,600,000
Change in unreconized tax benefit				3,200,000
Accrued interest related to unrecognized tax benefits included in income tax provision				21,200,000	11,400,000
Accrued interest related to uncertain tax positions	47,200,000			47,200,000	26,000,000
Tax adjustments, settlements, and unusual provisions			65,000,000
ATO proposed assessment	82,200,000			82,200,000
ATO proposed assessment tax	56,600,000			56,600,000
ATO proposed assessment penalties and interest	25,600,000			25,600,000
ATO assessment litigation deposit percentage	50.00%			50.00%
Deferred tax liabilities, undistributed foreign earnings	500,000,000			500,000,000	1,600,000,000
Taxes on repatriate of foreign earnings	$ 120,000,000			$ 120,000,000