COMMITMENTS AND CONTINGENCIES (Schedule Of Firm Transportation Contracts) (Details) MMBTU in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2019 USD ($) MMBTU
Long-term Purchase Commitment [Line Items]
2020	$ 18,352
2021	18,352
2022	18,095
2023	17,912
2024	11,342
Thereafter	83,686
Firm transportation contracts total	$ 167,739
Committed capacity, 2020 (in MMBtus) | MMBTU	45,750
Committed capacity, 2021 (in MMBtus) | MMBTU	45,625
Committed capacity, 2022 (in MMBtus) | MMBTU	40,275
Committed capacity, 2023 (in MMBtus) | MMBTU	36,500
Committed capacity, 2024 (in MMBtus) | MMBTU	36,600
Committed capacity, thereafter (in MMBtus) | MMBTU	413,850
Upstream
Long-term Purchase Commitment [Line Items]
2020	$ 12,236
2021	12,236
2022	12,236
2023	12,236
2024	5,666
Thereafter	19,358
Firm transportation contracts total	73,968
Midstream
Long-term Purchase Commitment [Line Items]
2020	6,116
2021	6,116
2022	5,859
2023	5,676
2024	5,676
Thereafter	64,328
Firm transportation contracts total	$ 93,771