Supplemental Financial Information - Prepaid Expenses and Other Current Assets (Detail) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Rig spare parts and supplies	$ 30,598	$ 25,343
Deferred rig start-up costs	52,544	61,488
Prepaid BOP lease	3,873	3,873
Prepaid insurance	3,808	3,771
Prepaid taxes	2,536	2,894
Other	4,444	4,777
Total	$ 97,803	$ 102,146