Commodity Derivative Contracts (Commodity Derivatives Outstanding Table) (Details)	Dec. 31, 2018 bbl / d $ / Barrel
Swap \| Year 2019 \| LLS [Member]
Derivative [Line Items]
Volume per day \| bbl / d	7,000
Weighted average swap price	66.57
Swap \| Year 2019 \| LLS [Member] \| Minimum
Derivative [Line Items]
Derivative, Swap Type, Fixed Price	60.00
Swap \| Year 2019 \| LLS [Member] \| Maximum
Derivative [Line Items]
Derivative, Swap Type, Fixed Price	74.90
Swap \| Year 2019 \| Q1-Q2 \| NYMEX [Member]
Derivative [Line Items]
Volume per day \| bbl / d	3,500
Weighted average swap price	59.05
Swap \| Year 2019 \| Q1-Q2 \| NYMEX [Member] \| Minimum
Derivative [Line Items]
Derivative, Swap Type, Fixed Price	59.00
Swap \| Year 2019 \| Q1-Q2 \| NYMEX [Member] \| Maximum
Derivative [Line Items]
Derivative, Swap Type, Fixed Price	59.10
Three-way Collar \| Year 2019 \| LLS [Member]
Derivative [Line Items]
Volume per day \| bbl / d	5,500
Weighted average sold put price	54.73
Weighted average floor price	63.09
Weighted average ceiling price	79.93
Three-way Collar \| Year 2019 \| LLS [Member] \| Minimum
Derivative [Line Items]
Derivative, Floor Price	62.00
Three-way Collar \| Year 2019 \| LLS [Member] \| Maximum
Derivative [Line Items]
Derivative, Cap Price	86.00
Three-way Collar \| Year 2019 \| Q1-Q2 \| NYMEX [Member]
Derivative [Line Items]
Volume per day \| bbl / d	18,500
Weighted average sold put price	48.84
Weighted average floor price	56.84
Weighted average ceiling price	69.94
Three-way Collar \| Year 2019 \| Q1-Q2 \| NYMEX [Member] \| Minimum
Derivative [Line Items]
Derivative, Floor Price	55.00
Three-way Collar \| Year 2019 \| Q1-Q2 \| NYMEX [Member] \| Maximum
Derivative [Line Items]
Derivative, Cap Price	75.45
Three-way Collar \| Year 2019 \| Q3-Q4 \| NYMEX [Member]
Derivative [Line Items]
Volume per day \| bbl / d	22,000
Weighted average sold put price	48.55
Weighted average floor price	56.55
Weighted average ceiling price	69.17
Three-way Collar \| Year 2019 \| Q3-Q4 \| NYMEX [Member] \| Minimum
Derivative [Line Items]
Derivative, Floor Price	55.00
Three-way Collar \| Year 2019 \| Q3-Q4 \| NYMEX [Member] \| Maximum
Derivative [Line Items]
Derivative, Cap Price	75.45
Three-way Collar \| Year 2020 \| NYMEX [Member]
Derivative [Line Items]
Volume per day \| bbl / d	1,000
Weighted average sold put price	50.00
Weighted average floor price	60.00
Weighted average ceiling price	82.50
Three-way Collar \| Year 2020 \| NYMEX [Member] \| Minimum
Derivative [Line Items]
Derivative, Floor Price	60.00
Three-way Collar \| Year 2020 \| NYMEX [Member] \| Maximum
Derivative [Line Items]
Derivative, Cap Price	82.65
Three-way Collar \| Year 2020 \| LLS [Member]
Derivative [Line Items]
Volume per day \| bbl / d	1,000
Weighted average sold put price	55.00
Weighted average floor price	65.00
Weighted average ceiling price	86.80
Three-way Collar \| Year 2020 \| LLS [Member] \| Minimum
Derivative [Line Items]
Derivative, Floor Price	65.00
Three-way Collar \| Year 2020 \| LLS [Member] \| Maximum
Derivative [Line Items]
Derivative, Cap Price	87.10

- Definition

Aggregate notional amount of derivative expressed in nonmonetary units. For example, the number of barrels specified in a fuel oil forward purchase contract.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Article 12
-Section 13
-Sentence Column B

+ Details

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- Definition

The average cap rate on a group of price risk derivatives such as caps or collars. A payment or receipt is triggered if the market rate exceeds the cap rate on the contract.

+ References

No definition available.

+ Details

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- Definition

The average floor rate on a group of price risk derivatives such as floors or collars. A payment or receipt is triggered if the market rate falls below the floor rate on the contract.

+ References

No definition available.

+ Details

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- Definition

The average strike price on the group of price risk option contracts such as put options or call options.

+ References

No definition available.

+ Details

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- Definition

The cap rate on a price risk derivative such as a cap or collar. A payment or receipt is triggered if the market rate exceeds the cap rate on the contract.

+ References

No definition available.

+ Details

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- Definition

Floor rate on a price risk derivative such as a floor or a collar. A payment or receipt is triggered if the market rate falls below the floor rate on the contract.

+ References

No definition available.

+ Details

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- Definition

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.

+ References

No definition available.

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- Definition

Average fixed price related to the group of price risk swap derivatives.

+ References

No definition available.

+ Details

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- Definition

Fixed price related to the price risk swap derivative.

+ References

No definition available.

+ Details

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