Financial Instruments and Risk Management (WTI Open Contracts) (Details)	3 Months Ended	9 Months Ended
	Mar. 31, 2016 bbl / d $ / bbl	Dec. 31, 2016 bbl / d $ / bbl
April - December, 2016 [Member]
Oil and Gas Delivery Commitments and Contracts [Line Items]
Volumes (barrels per day) | bbl / d	20,000
Swap Prices | $ / bbl	52.01
Scenario, Forecast [Member]
Oil and Gas Delivery Commitments and Contracts [Line Items]
Volumes (barrels per day) | bbl / d		5,000
Swap Prices | $ / bbl		45.30