Oil and Gas Properties Additional Details (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2016 USD ($) a well
Extractive Industries [Abstract]
Gain (loss) on disposition of proved property	$ (10,977)
Net mineral acres leased from others sold | a	190,960
Gross producing oil and gas wells sold | well	185
Net producing oil and gas wells sold | well	66
Proceeds from sale of oil and gas property and equipment	$ 32,227
Reimbursement of capital costs related to sale of in progress wells	3,269
Loss related to write-off of allocated goodwill	$ 7,244