Fair Value Measurement - Schedule of Assets and Liabilities Measured at Fair Value on a Recurring Basis (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Gross Fair Value, Assets		$ 12,105
Effect of Counterparty Netting, Assets	$ (2,226)	(11,648)
Net Carrying Value on Balance Sheet, Assets	48,038	457
Gross Fair Value, Liabilities	2,226	17,133
Effect of Counterparty Netting, Liabilities	(2,226)	(11,648)
Net Carrying Value on Balance Sheet, Liabilities	0	5,485
Commodity Derivative Instruments | Fair Value Measurements, Recurring Basis
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Effect of Counterparty Netting, Assets	(2,226)	(11,648)
Net Carrying Value on Balance Sheet, Assets	48,038	457
Effect of Counterparty Netting, Liabilities	(2,226)	(11,648)
Net Carrying Value on Balance Sheet, Liabilities	0	5,485
Commodity Derivative Instruments | Fair Value Measurements, Recurring Basis | Level 1
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Gross Fair Value, Assets	0	0
Gross Fair Value, Liabilities	0	0
Commodity Derivative Instruments | Fair Value Measurements, Recurring Basis | Level 2
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Gross Fair Value, Assets	50,264	12,105
Gross Fair Value, Liabilities	2,226	17,133
Commodity Derivative Instruments | Fair Value Measurements, Recurring Basis | Level 3
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Gross Fair Value, Assets	0	0
Gross Fair Value, Liabilities	$ 0	$ 0