Income Taxes - Components of Deferred Income Tax Assets and Liabilities (Detail) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Deferred tax assets:
Net operating loss carryforwards, or NOLs	$ 159,653	$ 143,231
Foreign tax credits	95,145	33,699
Worker's compensation and other current accruals	14,824	19,888
Bareboat charter deductions	23,353	32,469
UK depreciation deduction	21,222	17,358
Disputed receivables reserved	122	3,109
Deferred compensation	4,689	5,362
Foreign contribution taxes	3,857	3,630
Stock compensation awards	11,679	11,294
Deferred deductions	8,185	14,185
Interest - Uncertain Tax Positions	592	1,153
Other	1,812	2,089
Total deferred tax assets	345,133	287,467
Valuation allowance for NOLs	(91,219)	(93,191)
Valuation allowance for foreign tax credits	(62,400)
Valuation allowance for other deferred tax assets	(57,097)	(53,456)
Net deferred tax assets	134,417	140,820
Deferred tax liabilities:
Depreciation	(284,480)	(372,334)
Mobilization	(46,274)	(30,990)
Unbilled revenue	(38)	(13,971)
Undistributed earnings of foreign subsidiaries	(220)	(50)
Other	(416)	(4)
Total deferred tax liabilities	(331,428)	(417,349)
Net deferred tax liability	$ (197,011)	$ (276,529)