Supplemental Financial Information - Prepaid Expenses and Other Current Assets (Detail) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Deferred Costs Capitalized Prepaid And Other Assets Disclosure [Abstract]
Deferred contract costs	$ 78,707	$ 70,021
Prepaid taxes	54,786	54,412
Rig spare parts and supplies	18,085	20,256
Current contract assets	8,755	6,832
Prepaid insurance	1,609	2,742
Other	8,290	9,133
Total	$ 170,232	$ 163,396