Fresh Start Accounting Reorganization Items (Details) - USD ($) $ in Thousands	4 Months Ended	8 Months Ended	12 Months Ended
	Apr. 22, 2016	Dec. 31, 2016	Dec. 31, 2015
Predecessor [Member]
Fresh-Start Adjustment [Line Items]
Gain on settlement of liabilities subject to compromise	$ (863,938)		$ 0
Fair value of equity issued in excess of DIP principal	67,329		0
Fresh start adjustments	(222,512)		0
Reorganization legal and professional fees and expenses	25,573		0
Fair Value of Equity Issued for Backstop Fee	16,082		0
Debtor Reorganization Items, Write-off of Debt Issuance Costs and Debt Discounts	0		(6,565)
Other reorganization items	21,324		0
Gain (Loss) on Reorganization items, net	$ (956,142)		$ 6,565
Successor [Member]
Fresh-Start Adjustment [Line Items]
Gain on settlement of liabilities subject to compromise		$ 0
Fair value of equity issued in excess of DIP principal		0
Fresh start adjustments		0
Reorganization legal and professional fees and expenses		1,598
Fair Value of Equity Issued for Backstop Fee		0
Debtor Reorganization Items, Write-off of Debt Issuance Costs and Debt Discounts		0
Other reorganization items		41
Gain (Loss) on Reorganization items, net		$ 1,639