CONSOLIDATED STATEMENTS OF OPERATIONS (Parenthetical) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Operating costs and expenses
Depreciation and amortization - Proppant system rental	$ 1,029	$ 760
Depreciation and amortization - Proppant system services	63	34
Depreciation and amortization - Selling, general and administrative	$ 72	$ 75