Senior Notes (Details) - USD ($) $ in Thousands	3 Months Ended
Mar. 31, 2020	Mar. 31, 2019	Dec. 31, 2019
Senior Notes [Line Items]
Principal Amount, Net of Unamortized Deferred Financing Costs	$ 2,413,663		$ 2,453,035
Gain on extinguishment of debt	12,195	$ 0
Capitalized interest costs	$ 2,700	$ 4,900
6.125% Senior Notes due 2022 [Member]
Senior Notes [Line Items]
Senior Notes, interest rate, stated percentage	6.125%
Principal amount	$ 436,047		476,796
Unamortized deferred financing costs	(2,442)		(2,920)
Principal Amount, Net of Unamortized Deferred Financing Costs	433,605		473,876
Senior Notes, repurchased face amount	40,700
Senior Notes, repurchased settlement amount	28,300
Gain on extinguishment of debt	12,200
Discount realized on extinguishment of debt	12,400
Accelerated unamortized deferred financing costs on extinguishment of debt	$ 235
5.0% Senior Notes due 2024 [Member]
Senior Notes [Line Items]
Senior Notes, interest rate, stated percentage	5.00%
Principal amount	$ 500,000		500,000
Unamortized deferred financing costs	(3,535)		(3,766)
Principal Amount, Net of Unamortized Deferred Financing Costs	$ 496,465		496,234
5.625% Senior Notes due 2025 [Member]
Senior Notes [Line Items]
Senior Notes, interest rate, stated percentage	5.625%
Principal amount	$ 500,000		500,000
Unamortized deferred financing costs	(4,677)		(4,903)
Principal Amount, Net of Unamortized Deferred Financing Costs	$ 495,323		495,097
6.75% Senior Notes due 2026 [Member]
Senior Notes [Line Items]
Senior Notes, interest rate, stated percentage	6.75%
Principal amount	$ 500,000		500,000
Unamortized deferred financing costs	(5,362)		(5,571)
Principal Amount, Net of Unamortized Deferred Financing Costs	$ 494,638		494,429
6.625% Senior Notes due 2027 [Member]
Senior Notes [Line Items]
Senior Notes, interest rate, stated percentage	6.625%
Principal amount	$ 500,000		500,000
Unamortized deferred financing costs	(6,368)		(6,601)
Principal Amount, Net of Unamortized Deferred Financing Costs	493,632		493,399
Senior Notes
Senior Notes [Line Items]
Principal amount	2,436,047		2,476,796
Unamortized deferred financing costs	(22,384)		(23,761)
Principal Amount, Net of Unamortized Deferred Financing Costs	$ 2,413,663		$ 2,453,035

Discount realized on debt instrument that was repurchased.

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The non cash portion of gains (losses) recorded on the extinguishment of debt related to the acceleration of deferred financing costs.

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Face (par) amount of debt instrument at time of issuance.

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Contractual interest rate for funds borrowed, under the debt agreement.

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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Fair value amount of debt instrument that was repurchased.

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Face (par) amount of the original debt instrument that was repurchased.

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Difference between the fair value of payments made and the carrying amount of debt which is extinguished prior to maturity.

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Amount of interest capitalized during the period.

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Carrying value as of the balance sheet date of Notes with the highest claim on the assets of the issuer in case of bankruptcy or liquidation (with maturities initially due after one year or beyond the operating cycle if longer), excluding current portion. Senior note holders are paid off in full before any payments are made to junior note holders.

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The remaining balance of debt issuance expenses that were capitalized and are being amortized against income over the lives of the respective bond issues. This does not include the amounts capitalized as part of the cost of the utility plant or asset.

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