Income Taxes (Tables)

12 Months Ended

Dec. 31, 2016

Income Tax Disclosure [Abstract]

Schedule of deferred tax assets and liabilities

	December 31,
	2016			2015
Deferred tax assets:
Allowance for doubtful accounts	$	2,686		$	2,492
Tax credits	9,363			11,747
Other accruals	153,955			151,635
Net operating losses	304			337
Other	19,870			19,051
Total deferred tax assets	186,178			185,262
Deferred tax liabilities:
Inventories	76,694			82,313
Property and equipment	157,228			141,930
Other	42,422			40,791
Total deferred tax liabilities	276,344			265,034
Net deferred tax liabilities	$	(90,166	)	$	(79,772	)

Schedule of components of the provision for income taxes

	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

	For the Year Ended   December 31, 2015
	Current		Deferred			Total
Federal income tax expense (benefit)	$	504,558	$	(21,973	)	$	482,585
State income tax expense (benefit)	47,242		(677		)	46,565
Net income tax expense (benefit)	$	551,800	$	(22,650	)	$	529,150

	For the Year Ended   December 31, 2014
	Current		Deferred			Total
Federal income tax expense	$	399,271	$	5,987		$	405,258
State income tax expense (benefit)	43,242		(4,500		)	38,742
Net income tax expense	$	442,513	$	1,487		$	444,000

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

	For the Year Ended   December 31,
	2016			2015			2014
Federal income taxes at statutory rate	$	573,020		$	511,128		$	427,764
State income taxes, net of federal tax benefit	35,285			32,137			25,320
Other items, net	(8,805		)	(14,115		)	(9,084		)
Total provision for income taxes	$	599,500		$	529,150		$	444,000

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

	2016			2015			2014
Unrealized tax benefit, balance at January 1,	$	36,928		$	49,598		$	50,459
Additions based on tax positions related to the current year	6,116			5,405			4,665
Additions based on tax positions related to prior years	—			995			—
Payments related to items settled with taxing authorities	(195		)	(4,012		)	(300		)
Reductions due to the lapse of statute of limitations and settlements	(8,051		)	(15,058		)	(5,226		)
Unrealized tax benefit, balance at December 31,	$	34,798		$	36,928		$	49,598