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Senior Unsecured Notes (Details) - USD ($) $ / shares in Units, $ in Thousands |  |  |  |  |  |  |  |  | 12 Months Ended |
--- | --- | --- | --- | --- | --- | --- | --- | --- | --- | ---
Jun. 17, 2020 | May 05, 2020 | Aug. 20, 2018 | Sep. 12, 2016 | Aug. 12, 2016 | May 21, 2015 | Nov. 17, 2014 | May 20, 2013 | Dec. 31, 2020 | Dec. 31, 2019 | Dec. 31, 2018 | Dec. 31, 2016
Senior Notes [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Senior Notes, net |  |  |  |  |  |  |  |  | $ 2,121,319 | $ 2,610,298 |  |
Net gain on extinguishment of debt |  |  |  |  |  |  |  |  | 280,081 | 0 | $ (26,740) |
Senior Unsecured Notes [Member] |  |  |  |  |  |  |  |  |  |  |  |
Senior Notes [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Senior Notes, net |  |  |  |  |  |  |  |  | 1,660,663 | 2,610,298 |  |
Unamortized deferred financing costs |  |  |  |  |  |  |  |  | (13,918) | (38,998) |  |
Principal amount |  |  |  |  |  |  |  |  | 1,674,581 | $ 2,649,296 |  |
Senior Unsecured Notes, Repurchased face amount | $ 611,896 |  |  |  |  |  |  |  |  |  |  |
Senior Unsecured Notes, Redemption Price, Percentage |  | 80.00% |  |  |  |  |  |  |  |  |  |
Senior Unsecured Notes and 1.50% Senior Unsecured Convertible Notes Due 2021 [Member] |  |  |  |  |  |  |  |  |  |  |  |
Senior Notes [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Interest Paid, Senior Unsecured Notes, Accrued and Unpaid | 8,900 |  |  |  |  |  |  |  |  |  |  |
Senior Unsecured Notes and 1.50% Senior Unsecured Convertible Notes Due 2021 [Member] | Accelerated Unamortized Deferred Financing Costs [Member] |  |  |  |  |  |  |  |  |  |  |  |
Senior Notes [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Write off of Deferred Debt Issuance Cost | 5,600 |  |  |  |  |  |  |  |  |  |  |
Senior Unsecured Notes and 1.50% Senior Unsecured Convertible Notes Due 2021 [Member] | Accelerated Unamortized Debt Discount [Member] |  |  |  |  |  |  |  |  |  |  |  |
Senior Notes [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Write off of Deferred Debt Issuance Cost | 6,100 |  |  |  |  |  |  |  |  |  |  |
6.125% Senior Unsecured Notes Due 2022 and 5.0% Senior Unsecured Notes Due 2024 [Member] |  |  |  |  |  |  |  |  |  |  |  |
Senior Notes [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Senior Unsecured Notes, Repurchased face amount |  |  |  |  |  |  |  |  | 190,300 |  |  |
Senior Unsecured Notes, Repurchase Amount |  |  |  |  |  |  |  |  | 136,500 |  |  |
Senior Unsecured Notes, Repurchase Discount |  |  |  |  |  |  |  |  | (53,800) |  |  |
Net gain on extinguishment of debt |  |  |  |  |  |  |  |  | 52,800 |  |  |
6.125% Senior Unsecured Notes Due 2022 and 5.0% Senior Unsecured Notes Due 2024 [Member] | Accelerated Unamortized Deferred Financing Costs [Member] |  |  |  |  |  |  |  |  |  |  |  |
Senior Notes [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Write off of Deferred Debt Issuance Cost |  |  |  |  |  |  |  |  | $ 1,000 |  |  |
1.50% Senior Unsecured Convertible Notes Due 2021 [Member] |  |  |  |  |  |  |  |  |  |  |  |
Senior Notes [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Senior Notes, interest rate, stated percentage |  |  |  |  |  |  |  |  | 1.50% | 1.50% |  |
Senior Notes, net |  |  |  |  |  |  |  |  | $ 0 | $ 157,263 |  |
Unamortized deferred financing costs |  |  |  |  |  |  |  |  | 0 | (15,237) |  |
Principal amount |  |  |  |  | $ 172,500 |  |  |  | $ 0 | 172,500 |  |
Senior Unsecured Notes, Repurchased face amount | 107,000 |  |  |  |  |  |  |  |  |  |  |
Repayments of Senior Unsecured Notes | $ 53,500 |  |  |  |  |  |  |  |  |  |  |
Proceeds from Senior Unsecured Notes, Net of debt issuance costs |  |  |  |  | 166,600 |  |  |  |  |  |  |
Senior Notes debt issuance costs |  |  |  |  | 5,900 |  |  |  |  |  |  |
Senior Unsecured Convertible Notes, Initial fair value of liability component |  |  |  |  | $ 132,300 |  |  |  |  |  |  |
Senior Unsecured Convertible Notes, Effective interest rate |  |  |  |  | 7.25% |  |  |  |  |  |  |
Senior Unsecured Convertible Notes, Initial value of equity component |  |  |  |  | $ 40,200 |  |  |  |  |  |  |
Senior Unsecured Convertible Notes, Net carrying amount, Equity component |  |  |  |  |  |  |  |  |  | 33,600 |  |
Senior Convertible Notes, interest expense |  |  |  |  |  |  |  |  |  | 11,000 | 10,500 |
Capped call, Transaction costs |  |  |  |  | $ 24,200 |  |  |  |  |  |  |
Capped Call, Cap Price |  |  |  |  | $ 60.00 |  |  |  |  |  |  |
Senior Notes, unamortized debt discount |  |  |  |  |  |  |  |  |  | $ 13,900 |  |
6.125% Senior Unsecured Notes Due 2022 [Member] |  |  |  |  |  |  |  |  |  |  |  |
Senior Notes [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Senior Notes, interest rate, stated percentage | 6.125% |  |  |  |  |  | 6.125% |  | 6.125% | 6.125% |  |
Senior Notes, net |  |  |  |  |  |  |  |  | $ 211,548 | $ 473,876 |  |
Unamortized deferred financing costs |  |  |  |  |  |  |  |  | (855) | (2,920) |  |
Principal amount |  |  |  |  |  |  | $ 600,000 |  | 212,403 | $ 476,796 |  |
Senior Unsecured Notes, Repurchased face amount | $ 141,701 |  |  |  |  |  |  |  | 122,700 |  | 85,000 | $ 38,200
Senior Unsecured Notes, Repurchase Amount |  |  |  |  |  |  |  |  | $ 94,200 |  | $ 88,100 | $ 24,300
Proceeds from Senior Unsecured Notes, Net of debt issuance costs |  |  |  |  |  |  | 590,000 |  |  |  |  |
Senior Notes debt issuance costs |  |  |  |  |  |  | $ 10,000 |  |  |  |  |
5.0% Senior Unsecured Notes Due 2024 [Member] |  |  |  |  |  |  |  |  |  |  |  |
Senior Notes [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Senior Notes, interest rate, stated percentage | 5.00% |  |  |  |  |  |  | 5.00% | 5.00% | 5.00% |  |
Senior Notes, net |  |  |  |  |  |  |  |  | $ 275,458 | $ 496,234 |  |
Unamortized deferred financing costs |  |  |  |  |  |  |  |  | (1,576) | (3,766) |  |
Principal amount |  |  |  |  |  |  |  | $ 500,000 | 277,034 | $ 500,000 |  |
Senior Unsecured Notes, Repurchased face amount | $ 155,339 |  |  |  |  |  |  |  | 67,600 |  |  |
Senior Unsecured Notes, Repurchase Amount |  |  |  |  |  |  |  |  | $ 42,300 |  |  |
Proceeds from Senior Unsecured Notes, Net of debt issuance costs |  |  |  |  |  |  |  | 490,200 |  |  |  |
Senior Notes debt issuance costs |  |  |  |  |  |  |  | $ 9,800 |  |  |  |
5.625% Senior Unsecured Notes Due 2025 [Member] |  |  |  |  |  |  |  |  |  |  |  |
Senior Notes [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Senior Notes, interest rate, stated percentage | 5.625% |  |  |  |  | 5.625% |  |  | 5.625% | 5.625% |  |
Senior Notes, net |  |  |  |  |  |  |  |  | $ 346,326 | $ 495,097 |  |
Unamortized deferred financing costs |  |  |  |  |  |  |  |  | (2,792) | (4,903) |  |
Principal amount |  |  |  |  |  | $ 500,000 |  |  | $ 349,118 | $ 500,000 |  |
Senior Unsecured Notes, Repurchased face amount | $ 150,882 |  |  |  |  |  |  |  |  |  |  |
Proceeds from Senior Unsecured Notes, Net of debt issuance costs |  |  |  |  |  | 491,000 |  |  |  |  |  |
Senior Notes debt issuance costs |  |  |  |  |  | $ 9,000 |  |  |  |  |  |
6.75% Senior Unsecured Notes Due 2026 [Member] |  |  |  |  |  |  |  |  |  |  |  |
Senior Notes [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Senior Notes, interest rate, stated percentage | 6.75% |  |  | 6.75% |  |  |  |  | 6.75% | 6.75% |  |
Senior Notes, net |  |  |  |  |  |  |  |  | $ 415,265 | $ 494,429 |  |
Unamortized deferred financing costs |  |  |  |  |  |  |  |  | (3,970) | (5,571) |  |
Principal amount |  |  |  | $ 500,000 |  |  |  |  | $ 419,235 | $ 500,000 |  |
Senior Unsecured Notes, Repurchased face amount | $ 80,765 |  |  |  |  |  |  |  |  |  |  |
Proceeds from Senior Unsecured Notes, Net of debt issuance costs |  |  |  | 491,600 |  |  |  |  |  |  |  |
Senior Notes debt issuance costs |  |  |  | $ 8,400 |  |  |  |  |  |  |  |
6.625% Senior Unsecured Notes Due 2027 [Member] |  |  |  |  |  |  |  |  |  |  |  |
Senior Notes [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Senior Notes, interest rate, stated percentage | 6.625% |  | 6.625% |  |  |  |  |  | 6.625% | 6.625% |  |
Senior Notes, net |  |  |  |  |  |  |  |  | $ 412,066 | $ 493,399 |  |
Unamortized deferred financing costs |  |  |  |  |  |  |  |  | (4,725) | (6,601) |  |
Principal amount |  |  | $ 500,000 |  |  |  |  |  | $ 416,791 | $ 500,000 |  |
Senior Unsecured Notes, Repurchased face amount | $ 83,209 |  |  |  |  |  |  |  |  |  |  |
Proceeds from Senior Unsecured Notes, Net of debt issuance costs |  |  | 492,100 |  |  |  |  |  |  |  |  |
Senior Notes debt issuance costs |  |  | $ 7,900 |  |  |  |  |  |  |  |  |

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