Commitments and Contingencies - Additional Information (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Dec. 31, 2017	Dec. 03, 2015
Loss Contingencies [Line Items]
Loss contingency accrual	$ 5
Debt default description of event of default	if we become subject to any judgment, decree, order, governmental penalty or fine, this may constitute an event of default under the terms of our secured debt agreements and, following notice from the requisite lenders and/or noteholders, as applicable, result in our outstanding debt under the 2016 Term Loan Facility and 10% Second Lien Notes becoming immediately due and payable at par, and our outstanding debt under Convertible Notes becoming immediately due and payable at the make-whole amount specified in the indenture governing the Convertible Notes
Petrobras America, Inc.
Loss Contingencies [Line Items]
Loss contingency, disgorgement damages	$ 102
10% Second Lien Notes
Loss Contingencies [Line Items]
Debt Instrument, interest rate	10.00%	10.00%	10.00%