Bankruptcy Related Disclosures - Schedule of Reorganization Items Incurred (Details) - USD ($) $ in Thousands	4 Months Ended	7 Months Ended	8 Months Ended	12 Months Ended
	Dec. 31, 2017	Aug. 31, 2017	Aug. 31, 2017	Dec. 31, 2016
Fresh-Start Adjustment [Line Items]
Gain on extinguishment of debt	$ 0
Gain on fresh-start revaluation	0
Write-off of unamortized debt issuance costs and discounts	0
Prepayment penalties and debt-related fees	0
Professional fees	2,141
Key employee incentive plan	0
Reorganization items, net	$ 2,141
Predecessor
Fresh-Start Adjustment [Line Items]
Gain on extinguishment of debt			$ (89,989)
Gain on fresh-start revaluation			(16,566)
Write-off of unamortized debt issuance costs and discounts			10,262
Prepayment penalties and debt-related fees			13,191
Professional fees			7,342
Key employee incentive plan			1,229
Reorganization items, net			$ (74,531)	$ 0
Cash payment professional fees		$ 8,571
Cash used in debtor-in-possession financing costs		$ 3,673