Derivative Instruments - Additional Information (Details) $ in Thousands	6 Months Ended
	Jun. 30, 2019 USD ($) bbl Entity $ / bbl	Dec. 31, 2018 USD ($)
Derivative Instruments and Hedging Activities Disclosure [Line Items]
Derivative assets	$ 16,404	$ 991
Commodity contracts
Derivative Instruments and Hedging Activities Disclosure [Line Items]
Derivative assets	$ 6,500
Number of derivative counterparties | Entity	8
Commodity contracts | Crude Oil
Derivative Instruments and Hedging Activities Disclosure [Line Items]
Third-party quoted forward prices	WTI
Commodity contracts | Louisiana Light Sweet [Member]
Derivative Instruments and Hedging Activities Disclosure [Line Items]
Third-party quoted forward prices	LLS
Commodity contracts | MEH [Domain]
Derivative Instruments and Hedging Activities Disclosure [Line Items]
Third-party quoted forward prices	MEH
Third Quarter 2019 [Member] | Crude Oil
Derivative Instruments and Hedging Activities Disclosure [Line Items]
Derivative, Type of Instrument	Swaps-WTI
Derivative, Nonmonetary Notional Amount | bbl	7,397
Derivative, Swap Type, Average Fixed Price | $ / bbl	55.70
Derivative Instruments Not Designated as Hedging Instruments, Asset, at Fair Value	$ 0
Derivative Instruments Not Designated as Hedging Instruments, Liability, at Fair Value	$ 1,677
Third Quarter 2019 [Member] | Louisiana Light Sweet [Member]
Derivative Instruments and Hedging Activities Disclosure [Line Items]
Derivative, Type of Instrument	Swaps-LLS
Derivative, Nonmonetary Notional Amount | bbl	5,000
Derivative, Swap Type, Average Fixed Price | $ / bbl	59.17
Derivative Instruments Not Designated as Hedging Instruments, Asset, at Fair Value	$ 0
Derivative Instruments Not Designated as Hedging Instruments, Liability, at Fair Value	$ 1,589
Third Quarter 2019 [Member] | MEH [Domain]
Derivative Instruments and Hedging Activities Disclosure [Line Items]
Derivative, Nonmonetary Notional Amount | bbl	1,000
Derivative, Swap Type, Average Fixed Price | $ / bbl	64.00
Derivative Instruments Not Designated as Hedging Instruments, Asset, at Fair Value	$ 15
Derivative Instruments Not Designated as Hedging Instruments, Liability, at Fair Value	$ 0
Fourth Quarter 2019 [Member] | Crude Oil
Derivative Instruments and Hedging Activities Disclosure [Line Items]
Derivative, Type of Instrument	Swaps-WTI
Derivative, Nonmonetary Notional Amount | bbl	7,398
Derivative, Swap Type, Average Fixed Price | $ / bbl	55.70
Derivative Instruments Not Designated as Hedging Instruments, Asset, at Fair Value	$ 0
Derivative Instruments Not Designated as Hedging Instruments, Liability, at Fair Value	$ 1,222
Fourth Quarter 2019 [Member] | Louisiana Light Sweet [Member]
Derivative Instruments and Hedging Activities Disclosure [Line Items]
Derivative, Type of Instrument	Swaps-LLS
Derivative, Nonmonetary Notional Amount | bbl	5,000
Derivative, Swap Type, Average Fixed Price | $ / bbl	59.17
Derivative Instruments Not Designated as Hedging Instruments, Asset, at Fair Value	$ 0
Derivative Instruments Not Designated as Hedging Instruments, Liability, at Fair Value	$ 1,059
Fourth Quarter 2019 [Member] | MEH [Domain]
Derivative Instruments and Hedging Activities Disclosure [Line Items]
Derivative, Nonmonetary Notional Amount | bbl	1,000
Derivative, Swap Type, Average Fixed Price | $ / bbl	64.00
Derivative Instruments Not Designated as Hedging Instruments, Asset, at Fair Value	$ 46
Derivative Instruments Not Designated as Hedging Instruments, Liability, at Fair Value	$ 0
First Quarter 2020 [Member] | Crude Oil
Derivative Instruments and Hedging Activities Disclosure [Line Items]
Derivative, Type of Instrument	Swaps-WTI
Derivative, Nonmonetary Notional Amount | bbl	7,000
Derivative, Swap Type, Average Fixed Price | $ / bbl	54.94
Derivative Instruments Not Designated as Hedging Instruments, Asset, at Fair Value	$ 0
Derivative Instruments Not Designated as Hedging Instruments, Liability, at Fair Value	$ 1,048
First Quarter 2020 [Member] | MEH [Domain]
Derivative Instruments and Hedging Activities Disclosure [Line Items]
Derivative, Nonmonetary Notional Amount | bbl	2,000
Derivative, Swap Type, Average Fixed Price | $ / bbl	61.03
Derivative Instruments Not Designated as Hedging Instruments, Asset, at Fair Value	$ 0
Derivative Instruments Not Designated as Hedging Instruments, Liability, at Fair Value	$ 108
Second Quarter 2020 [Member] | Crude Oil
Derivative Instruments and Hedging Activities Disclosure [Line Items]
Derivative, Type of Instrument	Swaps-WTI
Derivative, Nonmonetary Notional Amount | bbl	7,000
Derivative, Swap Type, Average Fixed Price | $ / bbl	54.94
Derivative Instruments Not Designated as Hedging Instruments, Asset, at Fair Value	$ 0
Derivative Instruments Not Designated as Hedging Instruments, Liability, at Fair Value	$ 375
Second Quarter 2020 [Member] | MEH [Domain]
Derivative Instruments and Hedging Activities Disclosure [Line Items]
Derivative, Nonmonetary Notional Amount | bbl	2,000
Derivative, Swap Type, Average Fixed Price | $ / bbl	61.03
Derivative Instruments Not Designated as Hedging Instruments, Asset, at Fair Value	$ 0
Derivative Instruments Not Designated as Hedging Instruments, Liability, at Fair Value	$ 75
Third Quarter 2020 [Member] | Crude Oil
Derivative Instruments and Hedging Activities Disclosure [Line Items]
Derivative, Type of Instrument	Swaps-WTI
Derivative, Nonmonetary Notional Amount | bbl	7,000
Derivative, Swap Type, Average Fixed Price | $ / bbl	54.93
Derivative Instruments Not Designated as Hedging Instruments, Asset, at Fair Value	$ 164
Derivative Instruments Not Designated as Hedging Instruments, Liability, at Fair Value	$ 0
Third Quarter 2020 [Member] | MEH [Domain]
Derivative Instruments and Hedging Activities Disclosure [Line Items]
Derivative, Nonmonetary Notional Amount | bbl	2,000
Derivative, Swap Type, Average Fixed Price | $ / bbl	61.03
Derivative Instruments Not Designated as Hedging Instruments, Asset, at Fair Value	$ 0
Derivative Instruments Not Designated as Hedging Instruments, Liability, at Fair Value	$ 52
Fourth Quarter 2020 [Member] | Crude Oil
Derivative Instruments and Hedging Activities Disclosure [Line Items]
Derivative, Type of Instrument	Swaps-WTI
Derivative, Nonmonetary Notional Amount | bbl	7,000
Derivative, Swap Type, Average Fixed Price | $ / bbl	54.93
Derivative Instruments Not Designated as Hedging Instruments, Asset, at Fair Value	$ 569
Derivative Instruments Not Designated as Hedging Instruments, Liability, at Fair Value	$ 0
Fourth Quarter 2020 [Member] | MEH [Domain]
Derivative Instruments and Hedging Activities Disclosure [Line Items]
Derivative, Nonmonetary Notional Amount | bbl	2,000
Derivative, Swap Type, Average Fixed Price | $ / bbl	61.03
Derivative Instruments Not Designated as Hedging Instruments, Asset, at Fair Value	$ 0
Derivative Instruments Not Designated as Hedging Instruments, Liability, at Fair Value	$ 51