Commitments and Contingencies Commitments and Contigencies (Details) $ in Thousands	9 Months Ended
	Sep. 30, 2019 USD ($) MBbls MMcf
Supply Commitment
Dollar Commitment ($ in thousands) | $	$ 562,726
First Year Commitment [Member]
Supply Commitment
Dollar Commitment ($ in thousands) | $	93,528
Second Year Commitment [Member]
Supply Commitment
Dollar Commitment ($ in thousands) | $	98,999
Third Year Commitment [Member]
Supply Commitment
Dollar Commitment ($ in thousands) | $	98,223
Fourth Year Commitment [Member]
Supply Commitment
Dollar Commitment ($ in thousands) | $	85,204
commitments 5 years and beyond [Member]
Supply Commitment
Dollar Commitment ($ in thousands) | $	$ 186,772
First facilities agreement with midstream provider [Member]
Supply Commitment
incremental volume commitment	51.5
Second facilities agreement with midstream provider [Member]
Supply Commitment
incremental volume commitment	33.5
Natural Gas (MMcf) [Member]
Supply Commitment
Oil and Gas Delivery Commitments Volumes	286,806
Natural Gas (MMcf) [Member] | First Year Commitment [Member]
Supply Commitment
Oil and Gas Delivery Commitments Volumes	77,992
Natural Gas (MMcf) [Member] | Second Year Commitment [Member]
Supply Commitment
Oil and Gas Delivery Commitments Volumes	63,339
Natural Gas (MMcf) [Member] | Third Year Commitment [Member]
Supply Commitment
Oil and Gas Delivery Commitments Volumes	42,637
Natural Gas (MMcf) [Member] | Fourth Year Commitment [Member]
Supply Commitment
Oil and Gas Delivery Commitments Volumes	31,025
Natural Gas (MMcf) [Member] | commitments 5 years and beyond [Member]
Supply Commitment
Oil and Gas Delivery Commitments Volumes	71,813
Crude Oil (MBbls) [Member]
Supply Commitment
Oil and Gas Delivery Commitments Volumes	130,412
Crude Oil (MBbls) [Member] | First Year Commitment [Member]
Supply Commitment
Oil and Gas Delivery Commitments Volumes	19,322
Crude Oil (MBbls) [Member] | Second Year Commitment [Member]
Supply Commitment
Oil and Gas Delivery Commitments Volumes	22,846
Crude Oil (MBbls) [Member] | Third Year Commitment [Member]
Supply Commitment
Oil and Gas Delivery Commitments Volumes	24,272
Crude Oil (MBbls) [Member] | Fourth Year Commitment [Member]
Supply Commitment
Oil and Gas Delivery Commitments Volumes	21,978
Crude Oil (MBbls) [Member] | commitments 5 years and beyond [Member]
Supply Commitment
Oil and Gas Delivery Commitments Volumes	41,994
Wattenberg Field | Natural Gas (MMcf) [Member]
Supply Commitment
Oil and Gas Delivery Commitments Volumes	194,214
Wattenberg Field | Natural Gas (MMcf) [Member] | First Year Commitment [Member]
Supply Commitment
Oil and Gas Delivery Commitments Volumes	29,326
Wattenberg Field | Natural Gas (MMcf) [Member] | Second Year Commitment [Member]
Supply Commitment
Oil and Gas Delivery Commitments Volumes	31,025
Wattenberg Field | Natural Gas (MMcf) [Member] | Third Year Commitment [Member]
Supply Commitment
Oil and Gas Delivery Commitments Volumes	31,025
Wattenberg Field | Natural Gas (MMcf) [Member] | Fourth Year Commitment [Member]
Supply Commitment
Oil and Gas Delivery Commitments Volumes	31,025
Wattenberg Field | Natural Gas (MMcf) [Member] | commitments 5 years and beyond [Member]
Supply Commitment
Oil and Gas Delivery Commitments Volumes	71,813
Wattenberg Field | Natural Gas (MMcf) [Member] | Supply Contract Expiration Date [Member]
Supply Commitment
Supply Commitments Contract Expiration Date	Jun. 30, 2026
Wattenberg Field | Crude Oil (MBbls) [Member]
Supply Commitment
Oil and Gas Delivery Commitments Volumes | MBbls	95,281
Wattenberg Field | Crude Oil (MBbls) [Member] | First Year Commitment [Member]
Supply Commitment
Oil and Gas Delivery Commitments Volumes | MBbls	10,489
Wattenberg Field | Crude Oil (MBbls) [Member] | Second Year Commitment [Member]
Supply Commitment
Oil and Gas Delivery Commitments Volumes | MBbls	14,632
Wattenberg Field | Crude Oil (MBbls) [Member] | Third Year Commitment [Member]
Supply Commitment
Oil and Gas Delivery Commitments Volumes | MBbls	16,242
Wattenberg Field | Crude Oil (MBbls) [Member] | Fourth Year Commitment [Member]
Supply Commitment
Oil and Gas Delivery Commitments Volumes | MBbls	13,948
Wattenberg Field | Crude Oil (MBbls) [Member] | commitments 5 years and beyond [Member]
Supply Commitment
Oil and Gas Delivery Commitments Volumes | MBbls	39,970
Wattenberg Field | Crude Oil (MBbls) [Member] | Supply Contract Expiration Date [Member]
Supply Commitment
Supply Commitments Contract Expiration Date	Dec. 31, 2027
Wattenberg Field | Water (MBbls) [Member]
Supply Commitment
Oil and Gas Delivery Commitments Volumes | MBbls	31,850
Wattenberg Field | Water (MBbls) [Member] | First Year Commitment [Member]
Supply Commitment
Oil and Gas Delivery Commitments Volumes | MBbls	5,441
Wattenberg Field | Water (MBbls) [Member] | Second Year Commitment [Member]
Supply Commitment
Oil and Gas Delivery Commitments Volumes | MBbls	6,207
Wattenberg Field | Water (MBbls) [Member] | Third Year Commitment [Member]
Supply Commitment
Oil and Gas Delivery Commitments Volumes | MBbls	6,207
Wattenberg Field | Water (MBbls) [Member] | Fourth Year Commitment [Member]
Supply Commitment
Oil and Gas Delivery Commitments Volumes | MBbls	6,207
Wattenberg Field | Water (MBbls) [Member] | commitments 5 years and beyond [Member]
Supply Commitment
Oil and Gas Delivery Commitments Volumes | MBbls	7,788
Wattenberg Field | Water (MBbls) [Member] | Supply Contract Expiration Date [Member]
Supply Commitment
Supply Commitments Contract Expiration Date	Dec. 31, 2024
Delaware Basin | Natural Gas (MMcf) [Member]
Supply Commitment
Oil and Gas Delivery Commitments Volumes	72,112
Delaware Basin | Natural Gas (MMcf) [Member] | First Year Commitment [Member]
Supply Commitment
Oil and Gas Delivery Commitments Volumes	41,530
Delaware Basin | Natural Gas (MMcf) [Member] | Second Year Commitment [Member]
Supply Commitment
Oil and Gas Delivery Commitments Volumes	25,197
Delaware Basin | Natural Gas (MMcf) [Member] | Third Year Commitment [Member]
Supply Commitment
Oil and Gas Delivery Commitments Volumes	5,385
Delaware Basin | Natural Gas (MMcf) [Member] | Fourth Year Commitment [Member]
Supply Commitment
Oil and Gas Delivery Commitments Volumes	0
Delaware Basin | Natural Gas (MMcf) [Member] | commitments 5 years and beyond [Member]
Supply Commitment
Oil and Gas Delivery Commitments Volumes	0
Delaware Basin | Natural Gas (MMcf) [Member] | Supply Contract Expiration Date [Member]
Supply Commitment
Supply Commitments Contract Expiration Date	Dec. 31, 2021
Delaware Basin | Crude Oil (MBbls) [Member]
Supply Commitment
Oil and Gas Delivery Commitments Volumes | MBbls	35,131
Delaware Basin | Crude Oil (MBbls) [Member] | First Year Commitment [Member]
Supply Commitment
Oil and Gas Delivery Commitments Volumes | MBbls	8,833
Delaware Basin | Crude Oil (MBbls) [Member] | Second Year Commitment [Member]
Supply Commitment
Oil and Gas Delivery Commitments Volumes | MBbls	8,214
Delaware Basin | Crude Oil (MBbls) [Member] | Third Year Commitment [Member]
Supply Commitment
Oil and Gas Delivery Commitments Volumes | MBbls	8,030
Delaware Basin | Crude Oil (MBbls) [Member] | Fourth Year Commitment [Member]
Supply Commitment
Oil and Gas Delivery Commitments Volumes | MBbls	8,030
Delaware Basin | Crude Oil (MBbls) [Member] | commitments 5 years and beyond [Member]
Supply Commitment
Oil and Gas Delivery Commitments Volumes | MBbls	2,024
Delaware Basin | Crude Oil (MBbls) [Member] | Supply Contract Expiration Date [Member]
Supply Commitment
Supply Commitments Contract Expiration Date	Dec. 31, 2023
Appalachiain Basin | Natural Gas (MMcf) [Member]
Supply Commitment
Oil and Gas Delivery Commitments Volumes	20,480
Appalachiain Basin | Natural Gas (MMcf) [Member] | First Year Commitment [Member]
Supply Commitment
Oil and Gas Delivery Commitments Volumes	7,136
Appalachiain Basin | Natural Gas (MMcf) [Member] | Second Year Commitment [Member]
Supply Commitment
Oil and Gas Delivery Commitments Volumes	7,117
Appalachiain Basin | Natural Gas (MMcf) [Member] | Third Year Commitment [Member]
Supply Commitment
Oil and Gas Delivery Commitments Volumes	6,227
Appalachiain Basin | Natural Gas (MMcf) [Member] | Fourth Year Commitment [Member]
Supply Commitment
Oil and Gas Delivery Commitments Volumes	0
Appalachiain Basin | Natural Gas (MMcf) [Member] | commitments 5 years and beyond [Member]
Supply Commitment
Oil and Gas Delivery Commitments Volumes	0
Appalachiain Basin | Natural Gas (MMcf) [Member] | Supply Contract Expiration Date [Member]
Supply Commitment
Supply Commitments Contract Expiration Date	Aug. 31, 2022