Fair Value of Derivative Instruments on Condensed Consolidated Balance Sheets (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Derivatives, Fair Value [Line Items]
Derivative assets	$ 18,214	$ 34,932
Derivative liabilities	4,308	991
Derivative assets	4,311	10,100
Derivative Liability, Noncurrent	12	0
Derivative Liability	4,320	991
Derivative Asset	22,525	45,032
Commodity contracts
Derivatives, Fair Value [Line Items]
Derivative Liability	18,200
Commodity contracts \| Current Derivative Contract [Member]
Derivatives, Fair Value [Line Items]
Derivative assets	18,214	34,932
Derivative liabilities	4,308	991
Commodity contracts \| Noncurrent Derivative Contract [Member]
Derivatives, Fair Value [Line Items]
Derivative assets	4,311	10,100
Derivative Liability, Noncurrent	12	0
Fair Value, Measurements, Recurring \| Commodity contracts
Derivatives, Fair Value [Line Items]
Derivative assets	18,214	34,932
Derivative liabilities	(4,308)	(991)
Derivative assets	4,311	10,100
Derivative Liability, Noncurrent	$ 12	$ 0

Fair value, after the effects of master netting arrangements, of a financial asset or other contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset. Includes assets not subject to a master netting arrangement and not elected to be offset.

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