SUPPLEMENTAL CASH FLOWS INFORMATION (Tables)

12 Months Ended

Dec. 31, 2017

Supplemental Cash Flow Elements [Abstract]

Supplemental cash flow disclosures

	December 31,
($ in thousands)	2017		2016		2015
Supplemental cash flows disclosures
Interest paid	$	3,966	$	18,249	$	20,531
Income taxes paid	$	—	$	3	$	1,295
Supplemental disclosure of non‑cash activities
Capital expenditures included in accounts payable	$	33,850	$	3,176	$	8,821
Conversion of preferred stock to common stock at Initial Public Offering	$	162,511	$	—	$	—