Income Taxes (Tables)

12 Months Ended

Dec. 31, 2017

Income Tax Disclosure [Abstract]

Components of Earnings (Losses) from Continuing Operations Before Income Taxes and Noncontrolling Interests

Components of earnings (losses) from continuing operations before income taxes and noncontrolling interests are as follows (in thousands):

	Year Ended December 31,
	2017		2016		2015
United States	$	1,610,652	$	1,241,117	$	407,666
Foreign		139,305		57,542		(165,800	)
	$	1,749,957	$	1,298,659	$	241,866

Provision for Income Taxes

The provision for income taxes consists of the following (in thousands):

	Year Ended December 31,
	2017			2016			2015
Current:
Federal	$	504,865		$	286,224		$	285,856
State		37,308			27,353			4,618
Foreign		48,386			13,211			5,198
Total current		590,559			326,788			295,672
Deferred:
Federal		(207,006	)		71,777			(213,601	)
State		(4,533	)		5,193			(21,240	)
Foreign		(9,634	)		(5,515	)		(11,995	)
Total deferred		(221,173	)		71,455			(246,836	)
Total provision for income taxes	$	369,386		$	398,243		$	48,836

Reconciliation of the Federal Statutory Tax Rate to Total Provisions

A reconciliation of the federal statutory tax rate (35%) to the total provision is as follows:

	Year Ended December 31,
	2017			2016			2015
Taxes computed at statutory rate		35.00	%		35.00	%		35.00	%
State income taxes, net of federal income tax benefit		1.22	%		1.67	%		-5.02	%
Federal research credit		-0.24	%		-0.28	%		-1.47	%
Domestic manufacturing deduction		-2.58	%		-2.11	%		-9.98	%
Equity in losses of foreign joint venture		0.13	%		0.27	%		2.88	%
Impairment on investment in foreign joint venture		—			—			22.14	%
Foreign rate differential		-0.62	%		-1.05	%		-5.04	%
Noncontrolling interests		-1.24	%		-2.81	%		-16.27	%
Tax Reform Act		-10.01	%		—			—
Out-of-period correction		—			-0.22	%		-4.02	%
Other, net		-0.55	%		0.20	%		1.97	%
Provision for income taxes		21.11	%		30.67	%		20.19	%

Deferred Tax Assets and Liabilities

Deferred tax assets and liabilities resulted from the following (in thousands):

	December 31,
	2017			2016
Deferred tax assets:
Accrued liabilities and reserves	$	127,955		$	195,787
Allowance for doubtful accounts		15,136			15,511
Inventory		61,522			75,550
Post-retirement benefits		9,167			12,163
Commodity hedges		2,056			—
Net operating loss carryforward		19,895			11,544
Tax credit carryforwards		92,380			18,358
Valuation allowance		(96,107	)		—
Total deferred tax assets		232,004			328,913
Deferred tax liabilities:
Holdbacks and amounts not due under contracts		(10,214	)		(9,999	)
Commodity hedges		—			(316	)
Intangibles		(164,716	)		(246,697	)
Property, plant and equipment		(385,815	)		(630,500	)
Total deferred tax liabilities		(560,745	)		(887,512	)
Total net deferred tax liabilities	$	(328,741	)	$	(558,599	)

Reconciliation of the Beginning and Ending Amounts of Unrecognized Tax Benefits

A reconciliation of the beginning and ending amounts of unrecognized tax benefits recorded in deferred credits and other liabilities is as follows (in thousands):

	December 31,
	2017			2016			2015
Balance at beginning of year	$	44,088		$	50,510		$	63,001
Additions based on tax positions related to current year		11,154			6,157			6,508
Reductions based on tax positions related to current year		—			—			—
Additions based on tax positions related to prior years		2,556			147			241
Reductions based on tax positions related to prior years		(5,461	)		(8,201	)		(13,294	)
(Reductions) additions due to settlements with taxing authorities		—			(258	)		930
Reductions due to statute of limitations lapse		(3,492	)		(4,267	)		(6,876	)
Balance at end of year	$	48,845		$	44,088		$	50,510