|
Long-Term Debt (Details) (USD $)
In Thousands, unless otherwise specified |
Jun. 30, 2013
|
Dec. 31, 2012
|
Jun. 30, 2012
|
Dec. 31, 2010
|
|---|---|---|---|---|
| Debt Instrument [Line Items] | ||||
| Capital Lease Obligations, Current | $ 8,837 | $ 8,941 | ||
| Debt | 3,128,585 | 3,129,017 | ||
| Less amounts due in one year | (4,585) | (4,544) | ||
| Long-Term Debt | 3,124,000 | 3,124,473 | ||
| Accrued interest | 63,269 | 63,363 | ||
|
Senior Notes Due April 2017 at 8.00%
|
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| Debt Instrument [Line Items] | ||||
| Debt | 1,500,000 | 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 | ||
|
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
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| Debt Instrument [Line Items] | ||||
| Debt | 20,394 | 20,394 | ||
|
Other long-term notes maturing at various dates through 2031
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| Debt Instrument [Line Items] | ||||
| Debt | $ 5,326 | $ 5,758 |