Basis of Presentation and Significant Accounting Policies - Non-Cash Investing and Financing Activities and Supplemental Cash Flow Information (Details) - USD ($) $ in Thousands	4 Months Ended	8 Months Ended	12 Months Ended
	Dec. 31, 2017	Aug. 31, 2017	Dec. 31, 2016
Non-cash investing and financing activities:
Capital expenditures financed by accounts payable	$ 356
Reclassification of conversion option from debt to equity, net (Note 9)	43,716
Cash paid during the period for:
Interest	1,209
Income taxes	495
Cash received during the period for:
Income tax refunds	$ 49
Predecessor
Non-cash investing and financing activities:
Capital expenditures financed by accounts payable		$ 45	$ 59
Reclassification of conversion option from debt to equity, net (Note 9)		0	0
Cash paid during the period for:
Interest		13,332	31,404
Income taxes		1,889	2,434
Cash received during the period for:
Income tax refunds		$ 201	$ 500