Equity (Details) $ in Thousands							12 Months Ended
	Oct. 10, 2017 USD ($) a shares	Dec. 09, 2016 USD ($) shares	Mar. 11, 2016 USD ($) shares	Apr. 21, 2015 USD ($) shares	Apr. 06, 2015 shares	Feb. 27, 2015 shares	Dec. 31, 2017 USD ($) shares	Dec. 31, 2016 USD ($) shares	Dec. 31, 2015 USD ($)	Jun. 01, 2017 shares	May 31, 2017 shares	Apr. 02, 2015 shares	Apr. 01, 2015 shares
Subsidiary, Sale of Stock [Line Items]
Payments of Stock Issuance Costs | $	$ 300						$ 280	$ 847	$ 1,158
Sale of Stock, Consideration Received on Transaction | $		$ 145,800	$ 141,500
Adjustments to Additional Paid in Capital, Stock Issued, Issuance Costs | $		$ 400	$ 800				$ 280	$ 1,190	1,151
Common stock, shares authorized (in shares)							160,000,000	120,000,000
Issuance of Class A common stock, shares				7,000,000
Offering costs | $				$ 1,200
Proceeds from issuance of common stock | $				$ 187,600			$ 208,720	$ 288,510	188,720
Repayments of long-term debt | $							$ 0	$ 120,000	$ 476,982
Net Acres | a	6,600
Acquisition Costs, Period Cost | $	$ 38,000
Common Stock [Member]
Subsidiary, Sale of Stock [Line Items]
Sale of Stock, Number of Shares Issued in Transaction		6,000,000	7,500,000
Common stock, shares authorized (in shares)										160,000,000	120,000,000	120,000,000	80,000,000
Shares converted					1,500,000
Shares held in escrow					166,667
Harvey E Yates Company [Member]
Subsidiary, Sale of Stock [Line Items]
Shares issued upon conversion						10
Harvey E Yates Company [Member] | Convertible Preferred Stock [Member]
Subsidiary, Sale of Stock [Line Items]
Shares issued for acquisition						150,000
Shares issued as consideration in business combination						150,000
Harvey E Yates Company [Member] | Common Stock [Member]
Subsidiary, Sale of Stock [Line Items]
Shares issued for acquisition						3,300,000
Public Stock Offering [Member]
Subsidiary, Sale of Stock [Line Items]
Sale of Stock, Consideration Received on Transaction | $	$ 208,400
Public Stock Offering [Member] | Common Stock [Member]
Subsidiary, Sale of Stock [Line Items]
Sale of Stock, Number of Shares Issued in Transaction	8,000,000