CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Income Statement [Abstract]
Revenues	$ 610,506	$ 510,305	$ 1,780,004	$ 1,301,909
Operating expenses
Cost of revenues (excluding depreciation)	509,476	459,296	1,485,118	1,166,347
Operating expense (excluding depreciation)	51,718	51,240	153,741	125,325
Depreciation, depletion, and amortization	11,304	9,643	33,848	19,839
General and administrative expense (excluding depreciation)	11,292	9,863	34,688	31,654
Acquisition and integration expense	0	2,047	253	3,563
Total operating expenses	583,790	532,089	1,707,648	1,346,728
Operating income (loss)	26,716	(21,784)	72,356	(44,819)
Other income (expense)
Interest expense and financing costs, net	(7,419)	(11,232)	(25,500)	(21,951)
Loss on termination of financing agreements	0	0	(1,804)	0
Other income (expense), net	649	(56)	886	60
Change in value of common stock warrants	(975)	657	(2,211)	3,477
Change in value of contingent consideration	0	1,025	0	10,753
Equity earnings (losses) from Laramie Energy, LLC	553	3,659	11,651	(15,159)
Total other income (expense), net	(7,192)	(5,947)	(16,978)	(22,820)
Income (loss) before income taxes	19,524	(27,731)	55,378	(67,639)
Income tax benefit (expense)	(700)	(30)	(1,762)	8,117
Net income (loss)	$ 18,824	$ (27,761)	$ 53,616	$ (59,522)
Earnings (loss) per share
Basic (USD per share)	$ 0.41	$ (0.67)	$ 1.16	$ (1.44)
Diluted (USD per share)	$ 0.41	$ (0.67)	$ 1.16	$ (1.44)
Weighted-average number of shares outstanding
Basic (in shares)	45,561	41,580	45,505	41,309
Diluted (in shares)	51,992	41,580	45,527	41,309