Income Taxes (Tables)

12 Months Ended

Dec. 31, 2017

Income Tax Disclosure [Abstract]

Components of Net Deferred Taxes

The components of the net deferred taxes are as follows:

	2017			2016
Deferred tax assets
United States
Excess of net tax basis over remaining book basis	$	—		$	56,351
Deferred pension plan amounts	10,758			16,797
Accrued expenses not currently deductible	11,585			19,012
Other	2,150			6,803
Non-U.S.
Net operating loss carry forwards	—			3,800
Deferred pension plan amounts	134			3,120
Accrued expense not currently deductible	14,085			2,064
Deferred tax assets	38,712			107,947
Less: valuation allowance	—			(3,800		)
Net deferred tax assets	$	38,712		$	104,147
Deferred tax liabilities
United States
Excess of net book basis over remaining tax basis	$	(182,401	)	$	—
Other	(6,652		)	(7,672		)
Non-U.S.
Excess of net book basis over remaining tax basis	—			(200		)
Other	(402		)	(4,305		)
Deferred tax liabilities	(189,455		)	(12,177		)
Net deferred tax assets (liabilities)	$	(150,743	)	$	91,970

Income (Loss) from Continuing Operations Before Income Taxes

Income (loss) from continuing operations before income taxes consists of the following:

	Year Ended December 31,
	2017			2016			2015
United States	$	(81,329	)	$	(428,087	)	$	4,031
Non-U.S.	(368,485		)	(538,942		)	738,402
Total	$	(449,814	)	$	(967,029	)	$	742,433

Income Tax Provision for Continuing Operations

The income tax provision (benefit) for continuing operations consists of the following: 

	Year Ended December 31,
	2017			2016			2015
Current- United States	$	(227,707	)	$	61,928		$	113,648
Current- Non-U.S.	29,010			18,813			81,756
Deferred- United States	257,432			(189,880		)	(38,103		)
Deferred- Non-U.S.	(16,106		)	(17		)	1,931
Total	$	42,629		$	(109,156	)	$	159,232

Reconciliation of Reserve for Uncertain Tax Positions, Excluding Interest and Penalties

The following is a reconciliation of our reserve for uncertain tax positions, excluding interest and penalties. In 2016, we released an uncertain tax position in Libya in the gross amount of $40 million coupled with a related tax benefit of $13 million.

	2017			2016			2015
Gross balance at January 1,	$	159,826		$	169,687		$	108,812
Additions based on tax positions related to current year	14,187			15,665			31,022
Additions for tax positions of prior years	1,284			18,662			47,561
Reductions for tax positions of prior years	(860		)	(43,701		)	(11,945		)
Expiration of statutes	—			(487		)	(1,237		)
Tax settlements	—			—			(4,526		)
Gross balance at December 31,	174,437			159,826			169,687
Related tax benefits	(1,008		)	(1,008		)	(14,369		)
Net reserve at December 31,	$	173,429		$	158,818		$	155,318

Summary of Liabilities Related to Reserve for Uncertain Tax Positions

The liabilities related to our reserve for uncertain tax positions are comprised of the following:

	2017		2016
Reserve for uncertain tax positions, excluding interest and penalties	$	173,429	$	158,818
Interest and penalties included in “Other liabilities”	18,431		13,702
Reserve for uncertain tax positions, including interest and penalties	$	191,860	$	172,520

Schedule of Effective Tax Rate Reconciliation

A reconciliation of tax rates outside of the United Kingdom and the Cayman Islands to our Noble-UK effective rate for continuing operations is shown below:

	Year Ended December 31,
	2017		2016		2015
Effect of:
Tax rates which are different than the UK and Cayman Island rates	23.4	%	8.4	%	14.4	%
Tax impact of asset impairment	11.7	%	3.9	%	5.3	%
Tax impact of tax restructuring	(76.1	)%	—	%	—	%
Tax impact of tax reform	33.4	%	—	%	—	%
Reserve for (resolution of) tax authority audits	(1.9	)%	(1.0	)%	1.7	%
Total	(9.5	)%	11.3	%	21.4	%