Suspended Well Costs (Details) $ in Millions	9 Months Ended
	Sep. 30, 2015 USD ($)
Suspended Well Costs [Abstract]
Capitalized Exploratory Well Cost, Charged to Expense	$ (21.1)
Projects that have Exploratory Well Costs that have been Capitalized for Period Less than One Year, Number of Projects	2
Capitalized Exploratory Well Costs that Have Been Capitalized for Period Greater than One Year	$ 0.0