Long-Term Debt (Details) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2014	Dec. 31, 2013
Debt Instrument [Line Items]
Capital Lease Obligations, Current	$ 8,592	$ 8,498
Debt	3,218,448	3,118,920
Less amounts due in one year	(3,535)	(2,957)
Long-Term Debt	3,214,913	3,115,963
Accrued interest	52,859	63,272
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	1,250,000	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	1,600,000	0
Baltimore Port Facility revenue bonds in series due September 2025 at 5.75%
Debt Instrument [Line Items]
Debt	102,865	102,865
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	$ 4,401	$ 4,873

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

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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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