Drilling and Other Property and Equipment - Summary of Cost and Accumulated Depreciation of Drilling and Other Property and Equipment (Detail) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Property, Plant and Equipment [Line Items]
Property and equipment	$ 9,087,942	$ 9,751,401
Less accumulated depreciation	(3,361,007)	(3,372,587)
Drilling and other property and equipment, net	5,726,935	6,378,814	$ 6,945,953
Drilling Rigs and Equipment [Member]
Property, Plant and Equipment [Line Items]
Property and equipment	8,950,385	9,345,484
Construction Work-in-Progress [Member]
Property, Plant and Equipment [Line Items]
Property and equipment		269,605
Land and Buildings [Member]
Property, Plant and Equipment [Line Items]
Property and equipment	64,449	64,775
Office Equipment and Other [Member]
Property, Plant and Equipment [Line Items]
Property and equipment	$ 73,108	$ 71,537