Chapter 11 reorganization (Additional Information) (Details) - USD ($) $ / shares in Units, $ in Thousands	Mar. 21, 2017	Jan. 05, 2017
Reorganizations [Line Items]
Prior Senior Notes and associated accrued interest	$ 1,267,410
Mr. Mark Fischer, Founder and Former Chief Executive Officer
Reorganizations [Line Items]
Severance of cash and tangible asset amount		$ 4,038
New Common Stock
Reorganizations [Line Items]
Common stock shares issued (in shares)	44,982,142
Plan of Reorganization
Reorganizations [Line Items]
Prior Senior Notes and associated accrued interest	$ 1,267,410
General unsecured claims	2,439
Professional fees	6,954
Segregated account for professional fees attributable to our advisors	11,000
Plan of Reorganization | Prior Credit Facility
Reorganizations [Line Items]
Amount of repayments on prior credit facility	444,440
Plan of Reorganization | Exit Revolver
Reorganizations [Line Items]
Origination of the Exit Revolver	120,000
Plan of Reorganization | Exit Term Loan
Reorganizations [Line Items]
Origination of the Exit Revolver	150,000
Plan of Reorganization | Backstop Parties
Reorganizations [Line Items]
Gross proceeds from rights offering	$ 50,031
Plan of Reorganization | New Common Stock
Reorganizations [Line Items]
Percentage of common stock outstanding on conversion of debt	90.00%
Plan of Reorganization | New Common Stock | Mr. Mark Fischer, Founder and Former Chief Executive Officer
Reorganizations [Line Items]
Warrants issued for purchase of common stock (in shares)	140,023
Exercise price of warrants per share (in dollars per share)	$ 36.78
Plan of Reorganization | New Common Stock | Management Incentive Plan
Reorganizations [Line Items]
Percentage of shares authorized for issuance	7.00%
Plan of Reorganization | New Common Stock | Backstop Parties
Reorganizations [Line Items]
Percentage of rights issued on common stock outstanding	9.00%
Percentage of outstanding stock received as fee	1.00%