Income Taxes (Tables)

12 Months Ended

Dec. 31, 2018

Income Tax Disclosure [Abstract]

Schedule of Components of Income Tax Expense (Benefit)

The components of income tax expense (benefit) were as follows:

	For The Years Ended December 31,
	2018			2017			2016
Current:
U.S. Federal	$	20,634		$	65,856		$	(76,447	)
U.S. State	3,240			2,732			(1,924		)
Non-U.S.	1,436			2,030			1,411
	25,310			70,618			(76,960		)
Deferred:
U.S. Federal	(7,509		)	17,397			89,268
U.S. State	(8,973		)	(787		)	2,257
	(16,482		)	16,610			91,525
Total Income Tax Expense	$	8,828		$	87,228		$	14,565

Schedule of Reconciliation of Income Tax Expense (Benefit)

A reconciliation of income tax expense (benefit) and the amount computed by applying the statutory federal income tax rate of 21% to income from operations before income tax is:

	For the Years Ended December 31,
	2018					2017					2016
	Amount			Percent		Amount			Percent		Amount			Percent
Statutory U.S. federal income tax rate	$	39,399		21.0	%	$	59,429		35.0	%	$	22,755		35.0	%
State income taxes, net of federal tax benefit	3,240			1.7		1,264			0.7		997			1.5
Foreign income taxes	1,436			0.8		—			—		—			—
Excess tax depletion	(20,873		)	(11.1	)	(24,216		)	(14.3	)	(21,856		)	(33.6	)
Effect of domestic production activities	—			—		(6,493		)	(3.8	)	1,621			2.5
Effect of change in U.S. tax law	2,777			1.5		58,558			34.5		—			—
IRS and state tax examination settlements	—			—		—			—		13,958			21.5
Effect of valuation allowance	(1,379		)	(0.7	)	1,379			0.8		—			—
Research and development credit	(980		)	(0.5	)	—			—		—			—
Non-controlling interest	(5,420		)	(2.9	)	—			—		—			—
State rate change and prior period adjustments	(8,223		)	(4.4	)	—			—		—			—
Other	(1,149		)	(0.6	)	(2,693		)	(1.6	)	(2,910		)	(4.5	)
Income Tax Expense / Effective Rate	$	8,828		4.8	%	$	87,228		51.3	%	$	14,565		22.4	%

Schedule of Significant Components of Deferred Tax Assets and Liabilities

Significant components of deferred tax assets and liabilities were as follows:

	December 31,
	2018			2017
Deferred Tax Asset:
Postretirement benefits other than pensions	$	108,603		$	131,354
Asset retirement obligations	57,956			51,415
Pneumoconiosis benefits	41,632			36,160
Workers' compensation	16,016			16,778
Salary retirement	15,855			12,465
Mine subsidence	15,097			15,322
Financing	9,387			—
State bonus, net of Federal	6,042			4,473
Long-term disability	2,798			3,375
Other	6,669			7,924
Total Deferred Tax Asset	280,055			279,266
Valuation Allowance	—			(1,379		)
Net Deferred Tax Asset	280,055			277,887
Deferred Tax Liability:
Property, plant and equipment	(175,558		)	(174,806		)
Equity Partnerships	(16,638		)	(17,991		)
Advance mining royalties	(10,314		)	(10,025		)
Total Deferred Tax Liability	(202,510		)	(202,822		)
Net Deferred Tax Asset	$	77,545		$	75,065