| Fair Value, Measurement Inputs, Disclosure [Table Text Block] | The fair value of our debt instruments at September 30, 2011 and December 31, 2010 was as follows: | | | | | | | | | | September 30, 2011 | | December 31, 2010 | | (In thousands) | 7.875% Debentures due February 2013 | $ | 5,159 |
| | $ | 9,092 |
| 7.375% Senior Notes due October 2014 | 193,901 |
| | 194,244 |
| 6.75% Senior Notes due April 2015 | 143,629 |
| | 161,968 |
| 6.75% Senior Notes due April 2016 | 202,311 |
| | 216,653 |
| 7.0% Senior Notes due June 2017 | 306,063 |
| | 302,375 |
| 7.625% Senior Notes due October 2018 | 266,095 |
| | 262,500 |
| 7.0% Senior Notes due May 2019 | 254,375 |
| | 251,250 |
| 8.0% Senior Notes due November 2021 | 159,375 |
| | 158,063 |
| 7.5% Senior Notes due April 2027 | 189,000 |
| | 194,920 |
| Bank credit facility due March 2016 | 65,000 |
| | — |
| Mortgage notes and other debt, maturities through 2047 | 37,100 |
| | 37,991 |
| Total fair value of debt instruments | $ | 1,822,008 |
| | $ | 1,789,056 |
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