Related Party Transactions - Related Party Accounts Receivable and Accounts Payable (Detail) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Related Party Transaction [Line Items]
Total related party accounts receivable	$ 762	$ 408
Total related party accounts payable	1,844	2,553
Viking International Master Service Agreement [Member]
Related Party Transaction [Line Items]
Total related party accounts receivable		214
Total related party accounts payable		2,169
Riata Management Service Agreement [Member]
Related Party Transaction [Line Items]
Total related party accounts receivable	528	194
Total related party accounts payable	346	$ 384
PSIL MSA [Member]
Related Party Transaction [Line Items]
Total related party accounts receivable	234
Total related party accounts payable	1,315
Interest Payable on 2017 Notes [Member]
Related Party Transaction [Line Items]
Total related party accounts payable	$ 183