Fresh Start Accounting - Changes in accrued interest (Details) - Reorganization Adjustments $ in Thousands	Nov. 19, 2018 USD ($)
Fresh-Start Adjustment [Line Items]
Net change in accrued interest	$ (36,348)
Payment Of Accrued Interest \| 2013 Revolving Credit Facility And SSCF
Fresh-Start Adjustment [Line Items]
Net change in accrued interest	(35,994)
Payment Of Accrued Interest \| Debtor-In-Possession Financing
Fresh-Start Adjustment [Line Items]
Net change in accrued interest	$ (354)

Amount of fresh-start adjustment to other current liabilities.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 852
-SubTopic 10
-Section 55
-Paragraph 10
-URI http://asc.fasb.org/extlink&oid=84165509&loc=d3e56426-112766

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 852
-SubTopic 10
-Section 50
-Paragraph 7
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=6918054&loc=SL2890621-112765

Name:	us-gaap_FreshStartAdjustmentIncreaseDecreaseOtherCurrentLiabilities
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant