CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Cash flows from operating activities:
Net income (loss)	$ 27,786	$ (18,673)
Adjustments to reconcile net income (loss) to cash provided by operating activities:
Depreciation, depletion, and amortization	11,260	5,095
Non-cash interest expense	2,364	1,030
Change in value of common stock warrants	689	(1,644)
Change in value of contingent consideration	0	(6,176)
Deferred taxes	202	0
Stock-based compensation	2,536	2,185
Unrealized loss (gain) on derivative contracts	(1,488)	1,609
Equity (earnings) losses from Laramie Energy, LLC	(8,746)	1,871
Net changes in operating assets and liabilities:
Trade accounts receivable	6,362	10,466
Prepaid and other assets	32,050	43,994
Inventories	(94,743)	72,948
Obligations under inventory financing agreements	76,515	(84,623)
Accounts payable and other accrued liabilities	(29,792)	(16,053)
Net cash provided by operating activities	24,995	12,029
Cash flows from investing activities
Capital expenditures	(7,579)	(4,476)
Proceeds from sale of assets	0	2,235
Investment in Laramie Energy, LLC	0	(55,000)
Net cash used in investing activities	(7,579)	(57,241)
Cash flows from financing activities
Proceeds from sale of common stock, net of offering costs	(33)	0
Proceeds from borrowings	74,700	0
Repayments of borrowings	(91,636)	(5,114)
Net borrowings (repayments) on deferred payment arrangement	(1,912)	5,566
Purchase of common stock for retirement	(95)	(186)
Contingent consideration settlements	0	(1,084)
Net cash used in financing activities	(18,976)	(818)
Net decrease in cash and cash equivalents	(1,560)	(46,030)
Cash at beginning of period	47,772	167,788
Cash at end of period	46,212	121,758
Supplemental cash flow information:
Cash received (paid) for interest	(5,249)	(2,746)
Cash received (paid) for taxes	0	139
Non-cash investing and financing activities:
Accrued capital expenditures	$ 1,676	$ 2,439