Commitments (Schedule of Royalty Commitments) (Details)	12 Months Ended
	Dec. 31, 2019
up to 5,000 [Member]
Disclosure Of Commitments [Line Items]
Average Daily Production In Barrel	Up to 5,000
Description Of Applicable Production Royalty Rate	8%
5,000 to 125,000[Member]
Disclosure Of Commitments [Line Items]
Average Daily Production In Barrel	5,000 to 125,000
Description Of Applicable Production Royalty Rate	8% + (production - 5,000) * 0.1
125,000 to 400,000[Member]
Disclosure Of Commitments [Line Items]
Average Daily Production In Barrel	125,000 to 400,000
Description Of Applicable Production Royalty Rate	20%
400,000 to 600,000[Member]
Disclosure Of Commitments [Line Items]
Average Daily Production In Barrel	400,000 to 600,000
Description Of Applicable Production Royalty Rate	20% + (production - 400,000) * 0.025
Greater than 600,000[Member]
Disclosure Of Commitments [Line Items]
Average Daily Production In Barrel	Greater than 600,000
Description Of Applicable Production Royalty Rate	25%