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Long-Term Debt Senior Notes (Details) - USD ($) | 3 Months Ended | 9 Months Ended |  |  |
--- | --- | --- | --- | --- | ---
Sep. 30, 2016 | Mar. 31, 2016 | Sep. 30, 2015 | Sep. 30, 2016 | Sep. 30, 2015 | Aug. 12, 2016 | Jun. 30, 2016 | Dec. 31, 2015
Debt Instrument [Line Items] |  |  |  |  |  |  |  |
Debt Instrument, Face Amount | $ 2,803,736,000 |  |  | $ 2,803,736,000 |  |  |  | $ 2,350,000,000
Unamortized Debt Issuance Expense | (38,338,000) |  |  | (38,338,000) |  |  |  | (34,030,000)
Senior Notes, Noncurrent | 2,765,398,000 |  |  | 2,765,398,000 |  |  |  | 2,315,970,000
Gain (Loss) on Extinguishment of Debt | 0 |  | $ 0 | 15,722,000 | $ (16,578,000) |  |  |
Proceeds from Debt, Net of Issuance Costs |  |  |  | 166,681,000 | $ 0 |  |  |
Convertible Debt, Noncurrent | $ 128,925,000 |  |  | 128,925,000 |  |  |  | 0
Capped Call Transaction Costs |  |  |  | $ 24,183,000 |  |  |  |
Capped Call, Cap Price | $ 60.00 |  |  | $ 60.00 |  |  |  |
6.50% Senior Notes Due 2021 [Member] |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |
Debt Instrument, Face Amount | $ 346,955,000 |  |  | $ 346,955,000 |  |  |  | 350,000,000
Unamortized Debt Issuance Expense | (3,547,000) |  |  | (3,547,000) |  |  |  | (4,106,000)
Senior Notes, Noncurrent | 343,408,000 |  |  | 343,408,000 |  |  |  | 345,894,000
6.125% Senior Notes Due 2022 [Member] |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |
Debt Instrument, Face Amount | 561,796,000 |  |  | 561,796,000 |  |  |  | 600,000,000
Unamortized Debt Issuance Expense | (7,274,000) |  |  | (7,274,000) |  |  |  | (8,714,000)
Senior Notes, Noncurrent | 554,522,000 |  |  | 554,522,000 |  |  |  | 591,286,000
6.50% Senior Notes Due 2023 [Member] |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |
Debt Instrument, Face Amount | 394,985,000 |  |  | 394,985,000 |  |  |  | 400,000,000
Unamortized Debt Issuance Expense | (4,618,000) |  |  | (4,618,000) |  |  |  | (5,231,000)
Senior Notes, Noncurrent | 390,367,000 |  |  | 390,367,000 |  |  |  | 394,769,000
5% Senior Notes Due 2024 [Member] |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |
Debt Instrument, Face Amount | 500,000,000 |  |  | 500,000,000 |  |  |  | 500,000,000
Unamortized Debt Issuance Expense | (6,763,000) |  |  | (6,763,000) |  |  |  | (7,455,000)
Senior Notes, Noncurrent | 493,237,000 |  |  | 493,237,000 |  |  |  | 492,545,000
5.625% Senior Notes Due 2025 [Member] |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |
Debt Instrument, Face Amount | 500,000,000 |  |  | 500,000,000 |  |  |  | 500,000,000
Unamortized Debt Issuance Expense | (7,845,000) |  |  | (7,845,000) |  |  |  | (8,524,000)
Senior Notes, Noncurrent | 492,155,000 |  |  | 492,155,000 |  |  |  | 491,476,000
6.75% Senior Notes Due 2026 [Domain] |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |
Debt Instrument, Face Amount | 500,000,000 |  |  | 500,000,000 |  |  |  | 0
Unamortized Debt Issuance Expense | (8,291,000) |  |  | (8,291,000) |  |  |  | 0
Senior Notes, Noncurrent | 491,709,000 |  |  | 491,709,000 |  |  |  | 0
1.50% Senior Convertible Notes Due 2021 [Domain] |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |
Debt Instrument, Face Amount | $ 172,500,000 |  |  | 172,500,000 |  |  |  | 0
Senior Notes [Member] |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |
Debt Instrument, Covenant Compliance, Dividends Excluded From Computation |  |  |  | $ 6,500,000 |  |  |  |
Debt Instrument, Repurchased Face Amount |  | $ 46,300,000 |  |  |  |  |  |
Debt Instrument, Repurchased Settlement Amount |  | 29,900,000 |  |  |  |  |  |
Gain (Loss) on Extinguishment of Debt |  | 15,722,000 |  |  |  |  |  |
Debt Instrument, Repurchase Discount |  | 16,400,000 |  |  |  |  |  |
Amortization of Debt Issuance Costs Related to Repurchase of Debt Instrument |  | $ 700,000 |  |  |  |  |  |
Senior Notes [Member] | 6.50% Senior Notes Due 2021 [Member] |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |
Debt Instrument, Interest Rate, Stated Percentage | 6.50% |  |  | 6.50% |  |  |  |
Senior Notes [Member] | 6.125% Senior Notes Due 2022 [Member] |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |
Debt Instrument, Interest Rate, Stated Percentage | 6.125% |  |  | 6.125% |  |  |  |
Senior Notes [Member] | 6.50% Senior Notes Due 2023 [Member] |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |
Debt Instrument, Interest Rate, Stated Percentage | 6.50% |  |  | 6.50% |  |  |  |
Senior Notes [Member] | 5% Senior Notes Due 2024 [Member] |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |
Debt Instrument, Interest Rate, Stated Percentage | 5.00% |  |  | 5.00% |  |  |  |
Senior Notes [Member] | 5.625% Senior Notes Due 2025 [Member] |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |
Debt Instrument, Interest Rate, Stated Percentage | 5.625% |  |  | 5.625% |  |  |  |
Senior Notes [Member] | 6.75% Senior Notes Due 2026 [Domain] |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |
Debt Instrument, Interest Rate, Stated Percentage | 6.75% |  |  | 6.75% |  |  |  |
Debt Instrument, Face Amount | $ 500,000,000 |  |  | $ 500,000,000 |  |  |  |
Proceeds from Debt, Net of Paid and Accrued Issuance Costs |  |  |  | 491,600,000 |  |  |  |
Debt Issuance Costs, Gross | $ 8,400,000 |  |  | $ 8,400,000 |  |  |  |
Senior Notes [Member] | 1.50% Senior Convertible Notes Due 2021 [Domain] |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |
Debt Instrument, Interest Rate, Stated Percentage | 1.50% |  |  | 1.50% |  |  |  |
Convertible Debt [Member] | 1.50% Senior Convertible Notes Due 2021 [Domain] |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |
Debt Instrument, Face Amount | $ 172,500,000 |  |  | $ 172,500,000 |  |  |  |
Unamortized Debt Issuance Expense | (4,311,000) |  |  | (4,311,000) |  |  |  |
Debt Issuance Costs, Gross | 5,800,000 |  |  | 5,800,000 |  |  |  |
Proceeds from Debt, Net of Issuance Costs |  |  |  | $ 166,700,000 |  |  |  |
Debt Instrument, Convertible, Threshold Trading Days |  |  |  | 20 |  |  |  |
Debt Instrument, Convertible, Threshold Consecutive Trading Days |  |  |  | 30 days |  |  |  |
Debt Instrument, Convertible, Threshold Percentage of Stock Price Trigger |  |  |  | 130.00% |  |  |  |
Debt Instrument, Convertible, Threshold Business Days, Trading Price Trigger |  |  |  | 5 days |  |  |  |
Debt Instrument, Convertible, Threshold Trading Days, Trading Price Trigger |  |  |  | 5 days |  |  |  |
Debt Instrument, Principal Amount of Note | $ 1,000 |  |  | $ 1,000 |  |  |  |
Debt Instrument, Convertible, Threshold Percentage of Trading Price Trigger |  |  |  | 98.00% |  |  |  |
Debt Instrument, Convertible, Conversion Ratio |  |  |  | 24.6914 |  |  |  |
Debt Instrument, Convertible, Conversion Price | $ 40.50 |  |  | $ 40.50 |  |  |  |
Debt Instrument, Convertible, Comparable Yield |  |  |  | 7.25% |  |  |  |
Debt Instrument, Convertible, Initial Fair Value of Liability Component |  |  |  |  |  | $ 132,300,000 |  |
Debt Instrument, Convertible, Carrying Amount of Equity Component | $ (40,217,000) |  |  | $ (40,217,000) |  | $ (40,200,000) |  |
Amortization of Debt Discount (Premium) |  |  |  | 953,000 |  |  |  |
Convertible Debt, Noncurrent | 128,925,000 |  |  | 128,925,000 |  |  |  |
Revolving Credit Facility [Member] | Line of Credit [Member] |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |
Line of Credit Facility, Current Borrowing Capacity | $ 1,106,875,000 |  |  | $ 1,106,875,000 |  |  | $ 1,250,000,000 | $ 1,500,000,000
Debt Issuance Costs, Gross |  |  |  |  |  |  | $ 3,100,000 |

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