Income Taxes (Tables)

12 Months Ended

Dec. 31, 2019

Income Tax Disclosure [Abstract]

Components of Earnings Before Income Taxes and Noncontrolling Interests

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

	Year Ended December 31,
	2019			2018		2017
United States	$	1,806,704		$	3,160,111	$	1,610,652
Foreign		(23,897	)		69,280		139,305
	$	1,782,807		$	3,229,391	$	1,749,957

Provision for Income Taxes

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

	Year Ended December 31,
	2019			2018			2017
Current:
Federal	$	241,074		$	633,868		$	504,865
State		62,685			96,622			37,308
Foreign		8,981			14,800			48,386
Total current		312,740			745,290			590,559
Deferred:
Federal		101,946			4,953			(207,006	)
State		8,013			6,847			(4,533	)
Foreign		(10,802	)		(8,783	)		(9,634	)
Total deferred		99,157			3,017			(221,173	)
Total provision for income taxes	$	411,897		$	748,307		$	369,386

Reconciliation of the Federal Statutory Tax Rate to Total Provisions

A reconciliation of the federal statutory tax rate (21% in 2019 and 2018, and 35% in 2017) to the total provision is as follows:

	Year Ended December 31,
	2019	2018	2017
Taxes computed at statutory rate	21.00%	21.00%	35.00%
State income taxes, net of federal income tax benefit	3.16%	2.52%	1.22%
Federal research credit	-0.34%	-0.14%	-0.24%
Domestic manufacturing deduction	—	—	-2.58%
Equity in losses of foreign joint venture	0.19%	0.08%	0.13%
Foreign rate differential	—	-0.07%	-0.62%
Noncontrolling interests	-1.18%	-0.78%	-1.24%
Tax Reform Act	—	0.18%	-10.01%
Other, net	0.27%	0.38%	-0.55%
Provision for income taxes	23.10%	23.17%	21.11%

Deferred Tax Assets and Liabilities

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

	December 31,
	2019			2018
Deferred tax assets:
Accrued liabilities and reserves	$	146,658		$	128,553
Allowance for doubtful accounts		18,479			20,134
Inventory		79,363			63,950
Post-retirement benefits		10,288			8,746
Commodity hedges		5,164			1,393
Net operating loss carryforward		59,083			27,131
Tax credit carryforwards		164,132			16,792
Other deferred tax assets		8,508			779
Valuation allowance		(192,295	)		(30,104	)
Total deferred tax assets		299,380			237,374
Deferred tax liabilities:
Holdbacks and amounts not due under contracts		(12,930	)		(10,731	)
Intangibles		(171,531	)		(167,374	)
Property, plant and equipment		(545,890	)		(390,575	)
Total deferred tax liabilities		(730,351	)		(568,680	)
Total net deferred tax liabilities	$	(430,971	)	$	(331,306	)

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,
	2019			2018			2017
Balance at beginning of year	$	48,605		$	48,845		$	44,088
Additions based on tax positions related to current year		9,272			16,424			11,154
Reductions based on tax positions related to    current year		—			—			—
Additions based on tax positions related to prior years		2,106			199			2,556
Reductions based on tax positions related to    prior years		(2,863	)		(8,198	)		(5,461	)
Reductions due to settlements with taxing authorities		(1,514	)		(2,160	)		—
Reductions due to statute of limitations lapse		(4,686	)		(6,505	)		(3,492	)
Balance at end of year	$	50,920		$	48,605		$	48,845