Income Taxes (Tables)

12 Months Ended

Dec. 31, 2018

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,
	2018		2017		2016
United States	$	3,160,111	$	1,610,652	$	1,241,117
Foreign		69,280		139,305		57,542
	$	3,229,391	$	1,749,957	$	1,298,659

Provision for Income Taxes

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

	Year Ended December 31,
	2018			2017			2016
Current:
Federal	$	633,868		$	504,865		$	286,224
State		96,622			37,308			27,353
Foreign		14,800			48,386			13,211
Total current		745,290			590,559			326,788
Deferred:
Federal		4,953			(207,006	)		71,777
State		6,847			(4,533	)		5,193
Foreign		(8,783	)		(9,634	)		(5,515	)
Total deferred		3,017			(221,173	)		71,455
Total provision for income taxes	$	748,307		$	369,386		$	398,243

Reconciliation of the Federal Statutory Tax Rate to Total Provisions

A reconciliation of the federal statutory tax rate (21% in 2018 and 35% in 2017 and 2016) to the total provision is as follows:

	Year Ended December 31,
	2018			2017			2016
Taxes computed at statutory rate		21.00	%		35.00	%		35.00	%
State income taxes, net of federal income tax benefit		2.52	%		1.22	%		1.67	%
Federal research credit		-0.14	%		-0.24	%		-0.28	%
Domestic manufacturing deduction		0.00	%		-2.58	%		-2.11	%
Equity in losses of foreign joint venture		0.08	%		0.13	%		0.27	%
Foreign rate differential		-0.07	%		-0.62	%		-1.05	%
Noncontrolling interests		-0.78	%		-1.24	%		-2.81	%
Tax Reform Act		0.18	%		-10.01	%		0.00	%
Out-of-period correction		0.00	%		0.00	%		-0.22	%
Other, net		0.38	%		-0.55	%		0.20	%
Provision for income taxes		23.17	%		21.11	%		30.67	%

Deferred Tax Assets and Liabilities

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

	December 31,
	2018			2017
Deferred tax assets:
Accrued liabilities and reserves	$	128,553		$	127,955
Allowance for doubtful accounts		20,134			15,136
Inventory		63,950			61,522
Post-retirement benefits		8,746			9,167
Commodity hedges		1,393			2,056
Net operating loss carryforward		27,131			19,895
Tax credit carryforwards		16,792			92,380
Other deferred tax assets		779			—
Valuation allowance		(30,104	)		(96,107	)
Total deferred tax assets		237,374			232,004
Deferred tax liabilities:
Holdbacks and amounts not due under contracts	$	(10,731	)	$	(10,214	)
Intangibles		(167,374	)		(164,716	)
Property, plant and equipment		(390,575	)		(385,815	)
Total deferred tax liabilities		(568,680	)		(560,745	)
Total net deferred tax liabilities	$	(331,306	)	$	(328,741	)

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,
	2018			2017			2016
Balance at beginning of year	$	48,845		$	44,088		$	50,510
Additions based on tax positions related to current year		16,424			11,154			6,157
Reductions based on tax positions related to current year		—			—			—
Additions based on tax positions related to prior years		199			2,556			147
Reductions based on tax positions related to prior years		(8,198	)		(5,461	)		(8,201	)
Reductions due to settlements with taxing authorities		(2,160	)		—			(258	)
Reductions due to statute of limitations lapse		(6,505	)		(3,492	)		(4,267	)
Balance at end of year	$	48,605		$	48,845		$	44,088