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Fair Value Measurements Long-term Debt (Details) - USD ($) $ in Thousands | Sep. 30, 2018 | Aug. 20, 2018 | Dec. 31, 2017
--- | --- | --- | ---
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |  |
Properties held for sale, net | $ 5,040 |  | $ 111,700
6.50% Senior Notes due 2021 |  |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |  |
Senior Notes, interest rate, stated percentage | 6.50% |  |
6.125% Senior Notes due 2022 |  |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |  |
Senior Notes, interest rate, stated percentage | 6.125% |  |
6.50% Senior Notes due 2023 |  |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |  |
Senior Notes, interest rate, stated percentage | 6.50% |  |
5.0% Senior Notes due 2024 |  |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |  |
Senior Notes, interest rate, stated percentage | 5.00% |  |
5.625% Senior Notes due 2025 |  |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |  |
Senior Notes, interest rate, stated percentage | 5.625% |  |
6.75% Senior Notes due 2026 |  |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |  |
Senior Notes, interest rate, stated percentage | 6.75% |  |
Senior Notes | 6.50% Senior Notes due 2021 |  |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |  |
Senior Notes, interest rate, stated percentage | 6.50% |  |
Principal Amount | $ 0 |  | 344,611
Long-term Debt, Fair Value | $ 0 |  | 351,682
Senior Notes | 6.125% Senior Notes due 2022 |  |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |  |
Senior Notes, interest rate, stated percentage | 6.125% |  |
Principal Amount | $ 476,796 |  | 561,796
Long-term Debt, Fair Value | $ 491,076 |  | 571,627
Senior Notes | 6.50% Senior Notes due 2023 |  |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |  |
Senior Notes, interest rate, stated percentage | 6.50% |  |
Principal Amount | $ 0 |  | 394,985
Long-term Debt, Fair Value | $ 0 |  | 403,434
Senior Notes | 5.0% Senior Notes due 2024 |  |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |  |
Senior Notes, interest rate, stated percentage | 5.00% |  |
Principal Amount | $ 500,000 |  | 500,000
Long-term Debt, Fair Value | $ 491,000 |  | 483,440
Senior Notes | 5.625% Senior Notes due 2025 |  |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |  |
Senior Notes, interest rate, stated percentage | 5.625% |  |
Principal Amount | $ 500,000 |  | 500,000
Long-term Debt, Fair Value | $ 498,125 |  | 494,355
Senior Notes | 6.75% Senior Notes due 2026 |  |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |  |
Senior Notes, interest rate, stated percentage | 6.75% |  |
Principal Amount | $ 500,000 |  | 500,000
Long-term Debt, Fair Value | $ 522,150 |  | 516,350
Senior Notes | 6.625% Senior Notes due 2027 |  |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |  |
Senior Notes, interest rate, stated percentage | 6.625% |  |
Principal Amount | $ 500,000 | $ 500,000 | 0
Long-term Debt, Fair Value | $ 517,250 |  | 0
Convertible Debt [Member] | 1.50% Senior Convertible Notes Due 2021 [Member] |  |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |  |
Senior Notes, interest rate, stated percentage | 1.50% |  |
Principal Amount | $ 172,500 |  | 172,500
Long-term Debt, Fair Value | $ 191,044 |  | $ 168,291

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- Definition Face (par) amount of debt instrument at time of issuance. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 835 -SubTopic 30 -Section 45 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=114775744&loc=d3e28551-108399 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 835 -SubTopic 30 -Section 55 -Paragraph 8 -URI http://asc.fasb.org/extlink&oid=114775985&loc=d3e28878-108400 + Details
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- Definition Contractual interest rate for funds borrowed, under the debt agreement. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.22(a)(1)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 + Details
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- Definition The fair value amount of long-term debt whether such amount is presented as a separate caption or as a parenthetical disclosure. Additionally, this element may be used in connection with the fair value disclosures required in the footnote disclosures to the financial statements. The element may be used in both the balance sheet and disclosure in the same submission. + References No definition available. + Details
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