CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Income Statement [Abstract]
Revenues	$ 564,245	$ 413,793	$ 1,169,498	$ 791,604
Operating expenses
Cost of revenues (excluding depreciation)	474,353	364,662	975,642	707,051
Operating expense (excluding depreciation)	51,675	35,878	102,023	74,085
Depreciation, depletion, and amortization	11,284	5,100	22,544	10,196
General and administrative expense (excluding depreciation)	10,482	10,621	23,396	21,791
Acquisition and integration expense	0	845	253	1,516
Total operating expenses	547,794	417,106	1,123,858	814,639
Operating income (loss)	16,451	(3,313)	45,640	(23,035)
Other income (expense)
Interest expense and financing costs, net	(9,139)	(6,106)	(18,081)	(10,719)
Loss on termination of financing agreements	(1,804)	0	(1,804)	0
Other income, net	107	67	237	116
Change in value of common stock warrants	(547)	1,176	(1,236)	2,820
Change in value of contingent consideration	0	3,552	0	9,728
Equity earnings (losses) from Laramie Energy, LLC	2,352	(16,948)	11,098	(18,818)
Total other income (expense), net	(9,031)	(18,259)	(9,786)	(16,873)
Income (loss) before income taxes	7,420	(21,572)	35,854	(39,908)
Income tax benefit (expense)	(414)	8,484	(1,062)	8,147
Net income (loss)	$ 7,006	$ (13,088)	$ 34,792	$ (31,761)
Earnings (loss) per share
Basic (USD per share)	$ 0.15	$ (0.32)	$ 0.76	$ (0.77)
Diluted (USD per share)	$ 0.15	$ (0.32)	$ 0.75	$ (0.77)
Weighted-average number of shares outstanding
Basic (in shares)	45,541	41,015	45,505	40,991
Diluted (in shares)	45,564	41,015	45,536	40,991