| Schedule of Long-term Debt |
| | | | | | | | | | June 30,
2013 | | December 31,
2012 | Debt: | | | | Senior notes due April 2017 at 8.00%, issued at par value | $ | 1,500,000 |
| | $ | 1,500,000 |
| Senior notes due April 2020 at 8.25%, issued at par value | 1,250,000 |
| | 1,250,000 |
| Senior notes due March 2021 at 6.375%, issued at par value | 250,000 |
| | 250,000 |
| MEDCO revenue bonds in series due September 2025 at 5.75% | 102,865 |
| | 102,865 |
| Advance royalty commitments (7.43% weighted average interest rate for June 30, 2013 and December 31, 2012) | 20,394 |
| | 20,394 |
| Other long-term notes maturing at various dates through 2031 (total value of $6,612 and $7,300 less unamortized discount of $1,286 and $1,542 at June 30, 2013 and December 31, 2012, respectively). | 5,326 |
| | 5,758 |
| | 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 |
|
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