Income Taxes (Tables)

12 Months Ended

Dec. 31, 2018

Income Tax Disclosure [Abstract]

Schedule of deferred tax assets and liabilities

	December 31,
	2018			2017
Deferred tax assets:
Allowance for doubtful accounts	$	1,944		$	1,885
Tax credits	5,606			7,179
Other accruals	105,894			97,247
Net operating losses	—			346
Other	14,770			14,784
Total deferred tax assets	128,214			121,441
Deferred tax liabilities:
Inventories	62,846			55,965
Property and equipment	140,019			122,354
Other	30,915			28,528
Total deferred tax liabilities	233,780			206,847
Net deferred tax liabilities	$	(105,566	)	$	(85,406	)

Schedule of components of the provision for income taxes

	For the Year Ended   December 31, 2018
	Current		Deferred		Total
Federal income tax expense	$	289,953	$	16,309	$	306,262
State income tax expense	59,487		3,851		63,338
Net income tax expense	$	349,440	$	20,160	$	369,600

	For the Year Ended   December 31, 2017
	Current		Deferred			Total
Federal income tax expense (benefit)	$	467,577	$	(13,053	)	$	454,524
State income tax expense	41,183		8,293			49,476
Net income tax expense (benefit)	$	508,760	$	(4,760	)	$	504,000

	For the Year Ended   December 31, 2016
	Current		Deferred		Total
Federal income tax expense	$	540,090	$	7,558	$	547,648
State income tax expense	49,016		2,836		51,852
Net income tax expense	$	589,106	$	10,394	$	599,500

Reconciliation of the provision for income taxes to the amounts computed at the federal statutory rate

	For the Year Ended   December 31,
	2018			2017			2016
Federal income taxes at statutory rate	$	355,758		$	573,231		$	573,020
State income taxes, net of federal tax benefit	56,345			39,062			35,285
Excess tax benefit from share-based compensation	(34,703		)	(48,688		)	—
Revaluation of deferred tax liability	(1,262		)	(53,240		)	—
Other items, net	(6,538		)	(6,365		)	(8,805		)
Total provision for income taxes	$	369,600		$	504,000		$	599,500

Summary of changes in gross amount of unrecognized tax benefits, excluding interest and penalties

	2018			2017			2016
Unrealized tax benefit, balance at January 1,	$	35,388		$	34,798		$	36,928
Additions based on tax positions related to the current year	3,550			6,299			6,116
Additions based on tax positions related to prior years	4,255			—			—
Payments related to items settled with taxing authorities	(2,792		)	—			(195		)
Reductions due to the lapse of statute of limitations and settlements	(6,635		)	(5,709		)	(8,051		)
Unrealized tax benefit, balance at December 31,	$	33,766		$	35,388		$	34,798