Income Taxes (Tables)

12 Months Ended

Dec. 31, 2015

Income Tax Disclosure [Abstract]

Schedule of deferred tax assets and liabilities

	December 31,
	2015			2014
Deferred tax assets:
Allowance for doubtful accounts	$	2,492		$	2,357
Tax credits	11,747			14,725
Other accruals	151,635			131,436
Net operating losses	337			746
Other	19,051			16,468
Total deferred tax assets	185,262			165,732
Deferred tax liabilities:
Inventories	82,313			90,333
Property and equipment	141,930			139,604
Other	40,791			38,217
Total deferred tax liabilities	265,034			268,154
Net deferred tax liabilities	$	(79,772	)	$	(102,422	)

Schedule of components of the provision for income taxes

	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

	For the Year Ended   December 31, 2013
	Current		Deferred		Total
Federal income tax expense	$	348,303	$	847	$	349,150
State income tax expense	38,428		1,072		39,500
Net income tax expense	$	386,731	$	1,919	$	388,650

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

	For the Year Ended   December 31,
	2015			2014			2013
Federal income taxes at statutory rate	$	511,128		$	427,764		$	370,632
State income taxes, net of federal tax benefit	32,137			25,320			26,802
Other items, net	(14,115		)	(9,084		)	(8,784		)
Total provision for income taxes	$	529,150		$	444,000		$	388,650

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

	2015			2014			2013
Unrealized tax benefit, balance at January 1,	$	49,598		$	50,459		$	51,004
Additions based on tax positions related to the current year	5,405			4,665			7,046
Additions based on tax positions related to prior years	995			—			—
Payments related to items settled with taxing authorities	(4,012		)	(300		)	(1,056		)
Reductions due to the lapse of statute of limitations and settlements	(15,058		)	(5,226		)	(6,535		)
Unrealized tax benefit, balance at December 31,	$	36,928		$	49,598		$	50,459