Commitments and Contingencies Litigation (Details) $ in Millions	12 Months Ended
	Dec. 31, 2016 USD ($)
Commitments and Contingencies Disclosure [Abstract]
Overriding Royalty Interest	4.00%
Litigation Settlement, Amount	$ 16.7
Loss Contingency, Range of Possible Loss, Minimum	0.0
Loss Contingency, Estimate of Possible Loss, Maximum	$ 25.0