Long-Term Debt (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	9 Months Ended
Sep. 30, 2014	Dec. 31, 2013
Debt Instrument [Line Items]
Capital Lease Obligations, Current	$ 8,667	$ 8,498
Debt	3,239,730	3,118,920
Less amounts due in one year	(3,558)	(2,957)
Long-Term Debt	3,236,172	3,115,963
Accrued interest	93,709	63,272
Proceeds from Issuance of Private Placement	1,600,000
Debt, Weighted Average Interest Rate	5.90%
Debt Instrument, Convertible, Conversion Price	$ 1.0275
Proceeds from (Repayments of) Other Debt	235,200
Senior Notes Due April 2017 at 8.00%
Debt Instrument [Line Items]
Debt	0	1,500,000
Senior notes due April 2020 at 8.25%
Debt Instrument [Line Items]
Debt	1,014,800	1,250,000
Senior notes due March 2021 at 6.375%
Debt Instrument [Line Items]
Debt	250,000	250,000
Senior Secured Notes Due April 2022 Par Value [Member]
Debt Instrument [Line Items]
Debt	1,850,000	0
Baltimore Port Facility revenue bonds in series due September 2025 at 5.75%
Debt Instrument [Line Items]
Debt	102,865	102,865
Senior notes due April 2022 at 5.875%, Premium [Member]
Debt Instrument [Line Items]
Debt	6,875	0
Senior notes due April 2022 at 5.875%, Amortization of Bond Premium [Member]
Debt Instrument [Line Items]
Debt	(148)	0
Advance royalty commitments
Debt Instrument [Line Items]
Debt	11,182	11,182
Other long-term notes maturing at various dates through 2031
Debt Instrument [Line Items]
Debt	4,156	4,873
Additional Funding Agreement Terms [Member]
Debt Instrument [Line Items]
Proceeds from Issuance of Private Placement	$ 250,000

Amount of capital lease obligation due within one year or the normal operating cycle, if longer.

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The price per share of the conversion feature embedded in the debt instrument.

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Weighted average interest rate of debt outstanding.

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Carrying value as of the balance sheet date of [accrued] interest payable on all forms of debt, including trade payables, that has been incurred and is unpaid. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer).

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Carrying amount of long-term debt, net of unamortized discount or premium, including current and noncurrent amounts. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

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Amount of long-term debt, after unamortized discount or premium, scheduled to be repaid within one year or the normal operating cycle, if longer. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

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The cash inflow associated with the amount received from entity's raising of capital via private rather than public placement.

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The net cash inflow or outflow in other borrowings not otherwise defined in the taxonomy.

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