Oil and Gas Producing Activities (Unaudited) - Proved Developed and Undeveloped Oil and Gas Reserves (Details) bbl in Thousands, MMcf in Thousands	4 Months Ended
	Apr. 30, 2017 bbl MMcf
Natural Gas
Total proved reserves:
Beginning of year | MMcf	4,214
Crude oil and natural gas reserves sold | MMcf	(4,067)
Extensions, discoveries and other reserve additions | MMcf	42
Production | MMcf	(189)
End of year | MMcf	0
Crude Oil
Total proved reserves:
Beginning of year | bbl	187
Crude oil and natural gas reserves sold | bbl	(170)
Extensions, discoveries and other reserve additions | bbl	6
Production | bbl	(23)
End of year | bbl	0