Quarterly report pursuant to Section 13 or 15(d)

Derivative Instruments - Additional Information (Details)

v3.19.2
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