Income Taxes (Tables)

12 Months Ended

Dec. 31, 2014

Deferred Income Taxes and Tax Credits [Abstract]

Schedule of deferred tax assets and liabilities

	December 31,
	2014			2013
Deferred tax assets:
Current:
Allowance for doubtful accounts	$	2,357		$	1,997
Tax credits	3,250			1,636
Other accruals	67,468			61,100
Total current deferred tax assets	73,075			64,733
Noncurrent:
Tax credits	11,475			5,333
Net operating losses	746			1,180
Other accruals	63,968			59,176
Other	16,468			16,181
Total noncurrent deferred tax assets	92,657			81,870
Total deferred tax assets	165,732			146,603
Deferred tax liabilities:
Current:
Inventories	90,333			84,955
Total current deferred tax liabilities	90,333			84,955
Noncurrent:
Property and equipment	139,604			131,851
Other	38,217			30,732
Total noncurrent deferred tax liabilities	177,821			162,583
Total deferred tax liabilities	268,154			247,538
Net deferred tax liabilities	$	(102,422	)	$	(100,935	)

Reconciliation of net deferred tax assets (liabilities)

	December 31,
	2014			2013
Deferred tax assets - current	$	73,075		$	64,733
Deferred tax liabilities - current	(90,333		)	(84,955		)
Deferred tax liabilities - current	(17,258		)	(20,222		)
Deferred tax assets - noncurrent	92,657			81,870
Deferred tax liabilities - noncurrent	(177,821		)	(162,583		)
Deferred tax liabilities - noncurrent	(85,164		)	(80,713		)
Net deferred tax liabilities	$	(102,422	)	$	(100,935	)

Schedule of components of the provision for income taxes

	Current		Deferred			Total
2014
Federal	$	399,271	$	5,987		$	405,258
State	43,242		(4,500		)	38,742
	$	442,513	$	1,487		$	444,000
2013
Federal	$	348,303	$	847		$	349,150
State	38,428		1,072			39,500
	$	386,731	$	1,919		$	388,650
2012
Federal	$	311,631	$	10,030		$	321,661
State	35,982		(1,868		)	34,114
	$	347,613	$	8,162		$	355,775

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

	For the Year Ended   December 31,
	2014			2013			2012
Federal income taxes at statutory rate	$	427,764		$	370,632		$	329,532
State income taxes, net of federal tax benefit	25,320			26,802			22,426
Other items, net	(9,084		)	(8,784		)	3,817
Total provision for income taxes	$	444,000		$	388,650		$	355,775

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

	For the Year Ended   December 31,
	2014			2013			2012
Balance as of January 1,	$	50,459		$	51,004		$	45,800
Additions based on tax positions related to the current year	4,665			7,046			8,100
Additions based on tax positions related to prior years	—			—			1,301
Payments related to items settled with taxing authorities	(300		)	(1,056		)	(451		)
Reductions due to the lapse of statute of limitations and settlements	(5,226		)	(6,535		)	(3,746		)
Balance as of December 31,	$	49,598		$	50,459		$	51,004