Stockholders' Equity (Deficit) - Reclassifications From Accumulated Other Comprehensive Loss (Details) - USD ($) $ in Thousands	1 Months Ended	2 Months Ended	3 Months Ended	8 Months Ended	9 Months Ended
	Sep. 30, 2017	Aug. 31, 2017	Sep. 30, 2016	Aug. 31, 2017	Sep. 30, 2016
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Total reclassifications for the period, net of tax	$ 0
Predecessor
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Total reclassifications for the period, net of tax		$ 1,436	$ (456)	$ 1,008	$ (1,368)
Prior service cost
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Total before tax	0
Prior service cost | Predecessor
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Total before tax		(33)	(50)	(133)	(150)
Actuarial loss
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Total before tax	0
Actuarial loss | Predecessor
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Total before tax		1,326	(406)	998	(1,218)
Defined Benefit Pension and Postretirement Items
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Total before tax	0
Tax effect	0
Total reclassifications for the period, net of tax	$ 0
Defined Benefit Pension and Postretirement Items | Predecessor
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Total before tax		1,293	(456)	865	(1,368)
Tax effect		143	0	143	0
Total reclassifications for the period, net of tax		$ 1,436	$ (456)	$ 1,008	$ (1,368)