Fastenal (FAST) 10-Q 15 Oct 13 2013 Q3 Quarterly report Financial data

Document_and_Entity_Informatio

Document and Entity Information	9 Months Ended
	Sep. 30, 2013	Oct. 08, 2013
Document And Entity Information [Abstract]
Document Type	10-Q
Amendment Flag	FALSE
Document Period End Date	30-Sep-13
Document Fiscal Year Focus	2013
Document Fiscal Period Focus	Q3
Trading Symbol	fast
Entity Registrant Name	FASTENAL CO
Entity Central Index Key	815556
Current Fiscal Year End Date	-19
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding		296,742,069

Consolidated_Balance_Sheets

Consolidated Balance Sheets (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Current assets:
Cash and cash equivalents	$92,190	$79,611
Marketable securities	441	354
Trade accounts receivable, net of allowance for doubtful accounts of $8,403 and $6,728, respectively	453,652	372,159
Inventories	755,985	715,383
Deferred income tax assets	13,815	14,420
Other current assets	120,747	97,361
Prepaid income taxes	0	7,368
Total current assets	1,436,830	1,286,656
Property and equipment, less accumulated depreciation	611,051	516,427
Other assets, net	12,538	12,749
Total assets	2,060,419	1,815,832
Current liabilities:
Accounts payable	105,131	78,019
Accrued expenses	152,447	126,155
Income taxes payable	1,994	0
Total current liabilities	259,572	204,174
Deferred income tax liabilities	51,212	51,298
Stockholders' equity:
Preferred stock, 5,000,000 shares authorized	0	0
Common stock, 400,000,000 shares authorized, 296,742,069 and 296,564,382 shares issued and outstanding, respectively	2,968	2,966
Additional paid-in capital	68,125	61,436
Retained earnings	1,663,789	1,477,601
Accumulated other comprehensive income	14,753	18,357
Total stockholders' equity	1,749,635	1,560,360
Total liabilities and stockholders' equity	$2,060,419	$1,815,832

Consolidated_Balance_Sheets_Pa

Consolidated Balance Sheets (Parenthetical) (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Thousands, except Share data, unless otherwise specified
Statement of Financial Position [Abstract]
Trade accounts receivable, allowance for doubtful accounts	$8,403	$6,728
Preferred stock, shares authorized	5,000,000	5,000,000
Common stock, shares authorized	400,000,000	400,000,000
Common stock, shares issued	296,742,069	296,564,382
Common stock, shares outstanding	296,742,069	296,564,382

Consolidated_Statements_of_Ear

Consolidated Statements of Earnings (USD $)	3 Months Ended		9 Months Ended
In Thousands, except Share data, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Income Statement [Abstract]
Net sales	$858,424	$802,577	$2,512,346	$2,376,342
Cost of sales	415,029	388,202	1,204,350	1,152,639
Gross profit	443,395	414,375	1,307,996	1,223,703
Operating and administrative expenses	254,957	238,814	753,042	708,322
Gain on sale of property and equipment	-112	-158	-568	-266
Operating income	188,550	175,719	555,522	515,647
Interest income	118	117	733	357
Interest expense	-25	0	-61	0
Earnings before income taxes	188,643	175,836	556,194	516,004
Income tax expense	69,293	66,516	206,787	194,184
Net earnings	$119,350	$109,320	$349,407	$321,820
Basic net earnings per share	$0.40	$0.37	$1.18	$1.09
Diluted net earnings per share	$0.40	$0.37	$1.17	$1.08
Basic weighted average shares outstanding	296,842,771	296,237,956	296,755,815	295,964,359
Diluted weighted average shares outstanding	297,716,375	297,178,746	297,701,324	297,083,700

Consolidated_Statements_of_Com

Consolidated Statements of Comprehensive Income (USD $)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Statement of Comprehensive Income [Abstract]
Net earnings	$119,350	$109,320	$349,407	$321,820
Other comprehensive income (loss), net of tax:
Foreign currency translation adjustments (net of tax of $0 in 2013 and 2012)	3,668	4,598	-3,692	4,154
Change in marketable securities (net of tax of $0 in 2013 and 2012)	4	56	88	46
Comprehensive income	$123,022	$113,974	$345,803	$326,020

Consolidated_Statements_of_Com1

Consolidated Statements of Comprehensive Income (Parenthetical) (USD $)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Statement of Comprehensive Income [Abstract]
Foreign currency translation adjustments, tax	$0	$0	$0	$0
Change in marketable securities, tax	$0	$0	$0	$0

Consolidated_Statements_of_Cas

Consolidated Statements of Cash Flows (USD $)	9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012
Cash flows from operating activities:
Net earnings	$349,407	$321,820
Adjustments to reconcile net earnings to net cash provided by operating activities:
Depreciation of property and equipment	47,212	39,153
Gain on sale of property and equipment	-568	-266
Bad debt expense	7,087	7,240
Deferred income taxes	519	4,817
Stock based compensation	4,050	3,450
Excess tax benefits from stock based compensation	-2,682	-8,957
Amortization of non-compete agreements	290	445
Changes in operating assets and liabilities:
Trade accounts receivable	-88,580	-79,679
Inventories	-40,602	-29,676
Other current assets	-23,386	-10,301
Accounts payable	27,112	11,103
Accrued expenses	26,292	11,217
Income taxes	12,044	14,835
Other	-2,922	3,895
Net cash provided by operating activities	315,273	289,096
Cash flows from investing activities:
Purchase of property and equipment	-145,559	-88,323
Proceeds from sale of property and equipment	4,291	1,102
Net increase in marketable securities	-87	-63
Increase in other assets	-79	-122
Net cash used in investing activities	-141,434	-87,406
Cash flows from financing activities:
Borrowings under line of credit	100,000	0
Payments against line of credit	-100,000	0
Proceeds from exercise of stock options	9,039	23,785
Excess tax benefits from stock based compensation	2,682	8,957
Purchase of common stock	-9,080	0
Payment of dividends	-163,219	-156,810
Net cash used in financing activities	-160,578	-124,068
Effect of exchange rate changes on cash	-682	305
Net increase in cash and cash equivalents	12,579	77,927
Cash and cash equivalents at beginning of period	79,611	117,676
Cash and cash equivalents at end of period	92,190	195,603
Supplemental disclosure of cash flow information:
Cash paid during each period for interest	61	0
Cash paid during each period for income taxes	$192,408	$184,166

Basis_of_Presentation

Basis of Presentation	9 Months Ended
	Sep. 30, 2013
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Basis of Presentation	(1) Basis of Presentation
	The accompanying unaudited consolidated financial statements of Fastenal Company and subsidiaries (collectively referred to as the Company, Fastenal, or by terms such as we, our, or us) have been prepared in accordance with United States generally accepted accounting principles for interim financial information. They do not include all information and footnotes required by United States generally accepted accounting principles for complete financial statements. However, except as described herein, there has been no material change in the information disclosed in the notes to consolidated financial statements included in our consolidated financial statements as of and for the year ended December 31, 2012. In the opinion of management, all adjustments (consisting of normal recurring accruals) considered necessary for a fair presentation have been included.

Marketable_Securities

Marketable Securities	9 Months Ended
	Sep. 30, 2013
Financial Instruments And Marketable Securities [Abstract]
Marketable Securities	(2) Marketable Securities
	Due to the varying short-term cash needs of our business, we periodically have marketable securities. We value these assets utilizing a fair value hierarchy that prioritizes the inputs to valuation techniques used to measure fair value. The hierarchy gives the highest priority to unadjusted quoted prices in active markets for identical assets and liabilities (Level 1) and the lowest priority to measurements involving unobservable inputs (Level 3). The three levels of the fair value hierarchy are as follows:
	•	Level 1 inputs are observable inputs that reflect quoted prices (unadjusted) for identical assets or liabilities in active markets.
	•	Level 2 inputs include other inputs that are directly or indirectly observable in the marketplace.
	•	Level 3 inputs are unobservable inputs which are supported by little or no market activity.
	The level in the fair value hierarchy within which a fair value measurement falls is based on the lowest level input that is significant to the fair value measurement in its entirety.
	The following table presents the placement in the fair value hierarchy of assets that are measured at fair value on a recurring basis:
	September 30, 2013:	Total		Level 1	Level 2	Level 3
	Common stock	$	441	441	—	—
	Total available-for-sale securities	$	441	441	—	—
	December 31, 2012:	Total		Level 1	Level 2	Level 3
	Common stock	$	354	354	—	—
	Total available-for-sale securities	$	354	354	—	—
	September 30, 2012:	Total		Level 1	Level 2	Level 3
	Common stock	$	360	360	—	—
	Government and agency securities	26,868		26,868	—	—
	Total available-for-sale securities	$	27,228	27,228	—	—
	There were no transfers between levels during the nine and three month periods ended September 30, 2013 and 2012.
	As of September 30, 2013, December 31, 2012, and September 30, 2012, our financial assets that are measured at fair value on a recurring basis consisted of common stock and, in the case of September 30, 2012, debt securities.
	Marketable securities, all treated as available-for-sale securities, consist of the following:
	September 30, 2013:	Amortized		Gross	Gross	Fair value
		cost		unrealized	unrealized
				gains	losses
	Common stock	$	197	244	—	441
	Total available-for-sale securities	$	197	244	—	441
	December 31, 2012:	Amortized		Gross	Gross	Fair value
		cost		unrealized	unrealized
				gains	losses
	Common stock	$	197	157	—	354
	Total available-for-sale securities	$	197	157	—	354
	September 30, 2012:	Amortized		Gross	Gross	Fair value
		cost		unrealized	unrealized
				gains	losses
	Common stock	$	197	163	—	360
	Government and agency securities	26,868		—	—	26,868
	Total available-for-sale securities	$	27,065	163	—	27,228
	The unrealized gains and losses recorded in accumulated other comprehensive income and the realized gains and losses recorded in earnings were immaterial during the periods reported in these consolidated financial statements.
	Future maturities of our available-for-sale securities consist of the following:
		Less than 12 months			Greater than 12 months
	September 30, 2013:	Amortized		Fair	Amortized	Fair
		cost		value	cost	value
	Common stock	$	197	441	—	—
	Total available-for-sale securities	$	197	441	—	—

Stockholders_Equity

Stockholders' Equity	9 Months Ended
	Sep. 30, 2013
Stockholders' Equity Note [Abstract]
Stockholders' Equity	(3) Stockholders’ Equity
	Our authorized, issued, and outstanding shares (share amounts stated in whole numbers) consist of the following:
		Par Value		September 30,			December 31,			September 30,
				2013			2012			2012
	Preferred Stock	$0.01	/share
	Shares authorized			5,000,000			5,000,000			5,000,000
	Shares issued and outstanding			—			—			—
	Common Stock	$0.01	/share
	Shares authorized			400,000,000			400,000,000			400,000,000
	Shares issued and outstanding			296,742,069			296,564,382			296,307,832
	Dividends
	On October 8, 2013, our board of directors declared a dividend of $0.25 per share of common stock. This dividend is to be paid in cash on November 22, 2013 to shareholders of record at the close of business on October 25, 2013. Since 2011 we have paid quarterly dividends and, in 2012, we paid a supplemental dividend late in the year due to uncertainty related to future dividend tax rates in the United States. Our board of directors expects to continue paying quarterly dividends, provided the future determination as to payment of dividends will depend on the financial needs of the Company and such other factors as deemed relevant by the board of directors.
	The following table presents the dividends either paid previously or declared by our board of directors for future payment:
		2013			2012
	First quarter	$	0.1		$	0.17
	Second quarter	0.2			0.17
	Third quarter	0.25			0.19
	Fourth quarter	0.25			0.21
	Sub-Total	$	0.8		$	0.74
	Supplemental				0.5
	Total	$	0.8		$	1.24
	Stock Options
	The following tables summarize the details of grants made under our stock option plan of options that have been granted and are outstanding, and the assumptions used to value these options. All options granted were effective at the close of business on the date of grant.
				Option				Closing
				exercise				stock price			30-Sep-13
		Options		(strike)				on date			Options		Options
	Date of grant	granted		price				of grant			outstanding		vested
	April 16, 2013	205,000		$	54			$	49.25		177,500		—
	April 17, 2012	1,235,000		$	54			$	49.01		1,132,500		—
	April 19, 2011	410,000		$	35			$	31.78		360,000		—
	April 20, 2010	530,000		$	30			$	27.13		300,000		—
	April 21, 2009	790,000		$	27			$	17.61		413,600		173,600
	April 15, 2008	550,000		$	27			$	24.35		216,000		114,750
	April 17, 2007	4,380,000		$	22.5			$	20.15		1,796,005		1,126,505
	Total	8,100,000									4,395,605		1,414,855
	Date of grant	Risk-free		Expected life of		Expected			Expected		Estimated fair
		interest rate		option in years		dividend			stock		value of stock
						yield			volatility		option
	April 16, 2013	0.7	%	5		1.6	%		37.42	%	$	12.66
	April 17, 2012	0.9	%	5		1.4	%		39.25	%	$	13.69
	April 19, 2011	2.1	%	5		1.6	%		39.33	%	$	11.2
	April 20, 2010	2.6	%	5		1.5	%		39.1	%	$	8.14
	April 21, 2009	1.9	%	5		1	%		38.8	%	$	3.64
	April 15, 2008	2.7	%	5		1	%		30.93	%	$	7.75
	April 17, 2007	4.6	%	4.85		1	%		31.59	%	$	5.63
	All of the options in the tables above vest and become exercisable over a period of up to eight years. Each option will terminate, to the extent not previously exercised, 13 months after the end of the relevant vesting period.
	The fair value of each share-based option is estimated on the date of grant using a Black-Scholes valuation method that uses the assumptions listed above. The expected life is the average length of time over which we expect the employee groups will exercise their options, which is based on historical experience with similar grants. Expected volatilities are based on the movement of our stock over the most recent historical period equivalent to the expected life of the option. The risk-free interest rate is based on the U.S. Treasury rate over the expected life at the time of grant. The dividend yield is estimated over the expected life based on our current dividend payout, historical dividends paid, and expected future cash dividends.
	Compensation expense equal to the grant date fair value is recognized for all of these awards over the vesting period. The stock-based compensation expense for the nine month periods ended September 30, 2013 and 2012 was $4,050 and $3,450, respectively. Unrecognized compensation expense related to outstanding stock options as of September 30, 2013 was $17,273 and is expected to be recognized over a weighted average period of 4.92 years. Any future changes in estimated forfeitures will impact this amount.
	Earnings Per Share
	The following tables present a reconciliation of the denominators used in the computation of basic and diluted earnings per share and a summary of the options to purchase shares of common stock which were excluded from the diluted earnings calculation because they were anti-dilutive:
		Nine-month period					Three-month period
	Reconciliation	2013		2012			2013			2012
	Basic weighted average shares outstanding	296,755,815		295,964,359			296,842,771			296,237,956
	Weighted shares assumed upon exercise of stock options	945,509		1,119,341			873,604			940,790
	Diluted weighted average shares outstanding	297,701,324		297,083,700			297,716,375			297,178,746
		Nine-month period					Three-month period
	Summary of anti-dilutive options excluded	2013		2012			2013			2012
	Options to purchase shares of common stock	1,263,599		735,675			1,313,261			1,578,804
	Weighted average exercise price of options	$54.00		$54.00			$54.00			$49.43
	Any dilutive impact summarized above would relate to periods when the average market price of our stock exceeded the exercise price of the potentially dilutive option securities then outstanding.

Income_Taxes

Income Taxes	9 Months Ended
	Sep. 30, 2013
Income Tax Disclosure [Abstract]
Income Taxes	(4) Income Taxes
	Fastenal, or one of its subsidiaries, files income tax returns in the United States federal jurisdiction, numerous states, and various local and foreign jurisdictions. With limited exceptions, we are no longer subject to income tax examinations by taxing authorities for taxable years before 2010 in the case of United States federal and non-United States examinations and 2009 in the case of state and local examinations.
	As of September 30, 2013 and 2012, the Company had $4,692 and $4,254, respectively, of liabilities recorded related to unrecognized tax benefits. Included in this liability for unrecognized tax benefits is an immaterial amount for interest and penalties, both of which we classify as a component of income tax expense. The Company does not anticipate its total unrecognized tax benefits will change significantly during the next 12 months.

Operating_Leases

Operating Leases	9 Months Ended
	Sep. 30, 2013
Leases, Operating [Abstract]
Operating Leases	(5) Operating Leases
	We lease certain pick-up trucks under operating leases. These leases have a non-cancellable lease term of one year, with renewal options for up to 72 months. The pick-up truck leases include an early buy out clause we generally exercise, thereby giving the leases an effective term of 28-36 months. Certain operating leases for vehicles contain residual value guarantee provisions which would become due at the expiration of the operating lease agreement if the fair value of the leased vehicles is less than the guaranteed residual value. The aggregate residual value guarantee related to these leases is approximately $48,709. We believe the likelihood of funding the guarantee obligation under any provision of the operating lease agreements is remote, except for a $43 loss on disposal reserve provided at September 30, 2013. Our fleet also contains vehicles we estimate will settle at a gain. Gains on these vehicles will be recognized when we sell or dispose of the vehicle or at the end of the lease term.

Contingencies

Contingencies	9 Months Ended
	Sep. 30, 2013
Commitments and Contingencies Disclosure [Abstract]
Contingencies	(6) Contingencies
	As of September 30, 2013 there were no material litigation matters that we consider to be probable or reasonably estimable.

Subsequent_Events

Subsequent Events	9 Months Ended
	Sep. 30, 2013
Subsequent Events [Abstract]
Subsequent Events	(7) Subsequent Events
	On October 8, 2013, our board of directors declared a dividend of $0.25 per share. This dividend is discussed in footnote (3) 'Stockholders' Equity'.

Marketable_Securities_Tables

Marketable Securities (Tables)	9 Months Ended
	Sep. 30, 2013
Financial Instruments And Marketable Securities [Abstract]
Fair Value Hierarchy of Assets Measured on Recurring Basis	The following table presents the placement in the fair value hierarchy of assets that are measured at fair value on a recurring basis:
	September 30, 2013:	Total		Level 1	Level 2	Level 3
	Common stock	$	441	441	—	—
	Total available-for-sale securities	$	441	441	—	—
	December 31, 2012:	Total		Level 1	Level 2	Level 3
	Common stock	$	354	354	—	—
	Total available-for-sale securities	$	354	354	—	—
	September 30, 2012:	Total		Level 1	Level 2	Level 3
	Common stock	$	360	360	—	—
	Government and agency securities	26,868		26,868	—	—
	Total available-for-sale securities	$	27,228	27,228	—	—
Summary of Marketable Securities Treated as Available-for-Sale Securities	Marketable securities, all treated as available-for-sale securities, consist of the following:
	September 30, 2013:	Amortized		Gross	Gross	Fair value
		cost		unrealized	unrealized
				gains	losses
	Common stock	$	197	244	—	441
	Total available-for-sale securities	$	197	244	—	441
	December 31, 2012:	Amortized		Gross	Gross	Fair value
		cost		unrealized	unrealized
				gains	losses
	Common stock	$	197	157	—	354
	Total available-for-sale securities	$	197	157	—	354
	September 30, 2012:	Amortized		Gross	Gross	Fair value
		cost		unrealized	unrealized
				gains	losses
	Common stock	$	197	163	—	360
	Government and agency securities	26,868		—	—	26,868
	Total available-for-sale securities	$	27,065	163	—	27,228
Summary of Future Maturities of Available-For-Sale Securities	Future maturities of our available-for-sale securities consist of the following:
		Less than 12 months			Greater than 12 months
	September 30, 2013:	Amortized		Fair	Amortized	Fair
		cost		value	cost	value
	Common stock	$	197	441	—	—
	Total available-for-sale securities	$	197	441	—	—

Stockholders_Equity_Tables

Stockholders' Equity (Tables)	9 Months Ended
	Sep. 30, 2013
Stockholders' Equity Note [Abstract]
Summary of Authorized, Issued, and Outstanding Shares	Our authorized, issued, and outstanding shares (share amounts stated in whole numbers) consist of the following:
		Par Value		September 30,			December 31,			September 30,
				2013			2012			2012
	Preferred Stock	$0.01	/share
	Shares authorized			5,000,000			5,000,000			5,000,000
	Shares issued and outstanding			—			—			—
	Common Stock	$0.01	/share
	Shares authorized			400,000,000			400,000,000			400,000,000
	Shares issued and outstanding			296,742,069			296,564,382			296,307,832
Schedule of Dividends Paid Previously or Declared	The following table presents the dividends either paid previously or declared by our board of directors for future payment:
		2013			2012
	First quarter	$	0.1		$	0.17
	Second quarter	0.2			0.17
	Third quarter	0.25			0.19
	Fourth quarter	0.25			0.21
	Sub-Total	$	0.8		$	0.74
	Supplemental				0.5
	Total	$	0.8		$	1.24
Summary of Stock Options Granted	The following tables summarize the details of grants made under our stock option plan of options that have been granted and are outstanding, and the assumptions used to value these options. All options granted were effective at the close of business on the date of grant.
				Option				Closing
				exercise				stock price			30-Sep-13
		Options		(strike)				on date			Options		Options
	Date of grant	granted		price				of grant			outstanding		vested
	April 16, 2013	205,000		$	54			$	49.25		177,500		—
	April 17, 2012	1,235,000		$	54			$	49.01		1,132,500		—
	April 19, 2011	410,000		$	35			$	31.78		360,000		—
	April 20, 2010	530,000		$	30			$	27.13		300,000		—
	April 21, 2009	790,000		$	27			$	17.61		413,600		173,600
	April 15, 2008	550,000		$	27			$	24.35		216,000		114,750
	April 17, 2007	4,380,000		$	22.5			$	20.15		1,796,005		1,126,505
	Total	8,100,000									4,395,605		1,414,855
Summary of Fair Value Assumptions for Options Granted
	Date of grant	Risk-free		Expected life of		Expected			Expected		Estimated fair
		interest rate		option in years		dividend			stock		value of stock
						yield			volatility		option
	April 16, 2013	0.7	%	5		1.6	%		37.42	%	$	12.66
	April 17, 2012	0.9	%	5		1.4	%		39.25	%	$	13.69
	April 19, 2011	2.1	%	5		1.6	%		39.33	%	$	11.2
	April 20, 2010	2.6	%	5		1.5	%		39.1	%	$	8.14
	April 21, 2009	1.9	%	5		1	%		38.8	%	$	3.64
	April 15, 2008	2.7	%	5		1	%		30.93	%	$	7.75
	April 17, 2007	4.6	%	4.85		1	%		31.59	%	$	5.63
Reconciliation of Denominators used in Computation of Basic and Diluted Earnings Per Share	The following tables present a reconciliation of the denominators used in the computation of basic and diluted earnings per share and a summary of the options to purchase shares of common stock which were excluded from the diluted earnings calculation because they were anti-dilutive:
		Nine-month period					Three-month period
	Reconciliation	2013		2012			2013			2012
	Basic weighted average shares outstanding	296,755,815		295,964,359			296,842,771			296,237,956
	Weighted shares assumed upon exercise of stock options	945,509		1,119,341			873,604			940,790
	Diluted weighted average shares outstanding	297,701,324		297,083,700			297,716,375			297,178,746
Summary of Anti-Dilutive Options Excluded
		Nine-month period					Three-month period
	Summary of anti-dilutive options excluded	2013		2012			2013			2012
	Options to purchase shares of common stock	1,263,599		735,675			1,313,261			1,578,804
	Weighted average exercise price of options	$54.00		$54.00			$54.00			$49.43

Marketable_Securities_Fair_Val

Marketable Securities - Fair Value Hierarchy of Assets Measured on Recurring Basis (Details) (USD $)	Sep. 30, 2013	Dec. 31, 2012	Sep. 30, 2012
In Thousands, unless otherwise specified
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total available-for-sale securities	$441	$354	$27,228
Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total available-for-sale securities	441	354	27,228
Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total available-for-sale securities	0	0	0
Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total available-for-sale securities	0	0	0
Common stock [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total available-for-sale securities	441	354	360
Common stock [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total available-for-sale securities	441	354	360
Common stock [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total available-for-sale securities	0	0	0
Common stock [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total available-for-sale securities	0	0	0
Government and agency securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total available-for-sale securities			26,868
Government and agency securities [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total available-for-sale securities			26,868
Government and agency securities [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total available-for-sale securities			0
Government and agency securities [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total available-for-sale securities			$0

Marketable_Securities_Addition

Marketable Securities - Additional Information (Detail) (USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Financial Instruments And Marketable Securities [Abstract]
Dollar value of transfers between levels	$0	$0	$0	$0

Marketable_Securities_Summary_

Marketable Securities - Summary of Marketable Securities Treated as Available-for-Sale Securities (Details) (USD $)	Sep. 30, 2013	Dec. 31, 2012	Sep. 30, 2012
In Thousands, unless otherwise specified
Schedule of Available-for-sale Securities [Line Items]
Total available-for-sale securities, Amortized cost	$197	$197	$27,065
Total available-for-sale securities, Gross unrealized gains	244	157	163
Total available-for-sale securities, Gross unrealized losses	0	0	0
Total available-for-sale securities, Fair value	441	354	27,228
Common stock [Member]
Schedule of Available-for-sale Securities [Line Items]
Total available-for-sale securities, Amortized cost	197	197	197
Total available-for-sale securities, Gross unrealized gains	244	157	163
Total available-for-sale securities, Gross unrealized losses	0	0	0
Total available-for-sale securities, Fair value	441	354	360
Government and agency securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Total available-for-sale securities, Amortized cost			26,868
Total available-for-sale securities, Gross unrealized gains			0
Total available-for-sale securities, Gross unrealized losses			0
Total available-for-sale securities, Fair value			$26,868

Marketable_Securities_Summary_1

Marketable Securities - Summary of Future Maturities of Available-For-Sale Securities (Details) (USD $)	Sep. 30, 2013
In Thousands, unless otherwise specified
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale securities, Amortized cost, maturities less than twelve months	$197
Available-for-sale securities, Fair value, maturities less than twelve months	441
Available-for-sale securities, Amortized cost, maturities greater than twelve months	0
Available-for-sale securities, Fair value, maturities greater than twelve months	0
Common stock [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale securities, Amortized cost, maturities less than twelve months	197
Available-for-sale securities, Fair value, maturities less than twelve months	441
Available-for-sale securities, Amortized cost, maturities greater than twelve months	0
Available-for-sale securities, Fair value, maturities greater than twelve months	$0

Stockholders_Equity_Summary_of

Stockholders' Equity - Summary of Authorized, Issued, and Outstanding Shares (Details) (USD $)	Sep. 30, 2013	Dec. 31, 2012	Sep. 30, 2012
Stockholders' Equity Note [Abstract]
Preferred stock, par value per share	$0.01	$0.01	$0.01
Preferred stock, shares authorized	5,000,000	5,000,000	5,000,000
Preferred stock, shares issued	0	0	0
Preferred stock, shares outstanding	0	0	0
Common stock, par value per share	$0.01	$0.01	$0.01
Common stock, shares authorized	400,000,000	400,000,000	400,000,000
Common stock, shares issued	296,742,069	296,564,382	296,307,832
Common stock, shares outstanding	296,742,069	296,564,382	296,307,832

Stockholders_Equity_Additional

Stockholders' Equity - Additional Information (Detail) (USD $)	9 Months Ended		0 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Oct. 08, 2013
			Subsequent Event [Member]
Schedule of Shareholders' Equity [Line Items]
Dividend declared date			8-Oct-13
Dividend declared per share			$0.25
Dividends payment date			22-Nov-13
Dividends payable record date			25-Oct-13
Options vesting and exercisable period, maximum (in years)	8 years
Options termination period after the end of the relevant vesting period (in months)	13 months
Total stock-based compensation expense for the Fastenal stock option plan	$4,050	$3,450
Total unrecognized compensation expense	$17,273
Weighted average period over which total unrecognized compensation expense will be recognized (in years)	4 years 11 months 1 day

Stockholders_Equity_Schedule_o

Stockholders' Equity - Schedule of Dividends Paid Previously or Declared (Details) (USD $)	3 Months Ended							12 Months Ended	0 Months Ended	9 Months Ended
	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2012	Oct. 08, 2013	Oct. 08, 2013
									Subsequent Event [Member]	Subsequent Event [Member]
Stockholders' Equity Note [Abstract]
Dividends paid per share	$0.25	$0.20	$0.10	$0.21	$0.19	$0.17	$0.17	$1.24
Sub-Total								$0.74
Supplemental dividend paid per share				$0.50
Subsequent Event [Line Items]
Dividend declared per share									$0.25
Sub-Total										$0.80
Dividend paid previously or declared, per share										$0.80

Stockholders_Equity_Summary_of1

Stockholders' Equity - Summary of Stock Options Granted (Details) (USD $)	77 Months Ended	9 Months Ended
	Sep. 30, 2013	Sep. 30, 2013	Sep. 30, 2013	Sep. 30, 2013	Sep. 30, 2013	Sep. 30, 2013	Sep. 30, 2013	Sep. 30, 2013
		April 16, 2013 [Member]	April 17, 2012 [Member]	April 19, 2011 [Member]	April 20, 2010 [Member]	April 21, 2009 [Member]	April 15, 2008 [Member]	April 17, 2007 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options granted	8,100,000	205,000	1,235,000	410,000	530,000	790,000	550,000	4,380,000
Option exercise (strike) price		$54	$54	$35	$30	$27	$27	$22.50
Closing stock price on date of grant		$49.25	$49.01	$31.78	$27.13	$17.61	$24.35	$20.15
Options outstanding	4,395,605	177,500	1,132,500	360,000	300,000	413,600	216,000	1,796,005
Options vested	1,414,855	0	0	0	0	173,600	114,750	1,126,505

Stockholders_Equity_Summary_of2

Stockholders' Equity - Summary of Fair Value Assumptions for Options Granted (Details) (USD $)	9 Months Ended
	Sep. 30, 2013
April 16, 2013 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Risk-free interest rate	0.70%
Expected life of option in years	5 years
Expected dividend yield	1.60%
Expected stock volatility	37.42%
Estimated fair value of stock option	$12.66
April 17, 2012 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Risk-free interest rate	0.90%
Expected life of option in years	5 years
Expected dividend yield	1.40%
Expected stock volatility	39.25%
Estimated fair value of stock option	$13.69
April 19, 2011 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Risk-free interest rate	2.10%
Expected life of option in years	5 years
Expected dividend yield	1.60%
Expected stock volatility	39.33%
Estimated fair value of stock option	$11.20
April 20, 2010 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Risk-free interest rate	2.60%
Expected life of option in years	5 years
Expected dividend yield	1.50%
Expected stock volatility	39.10%
Estimated fair value of stock option	$8.14
April 21, 2009 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Risk-free interest rate	1.90%
Expected life of option in years	5 years
Expected dividend yield	1.00%
Expected stock volatility	38.80%
Estimated fair value of stock option	$3.64
April 15, 2008 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Risk-free interest rate	2.70%
Expected life of option in years	5 years
Expected dividend yield	1.00%
Expected stock volatility	30.93%
Estimated fair value of stock option	$7.75
April 17, 2007 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Risk-free interest rate	4.60%
Expected life of option in years	4 years 10 months 6 days
Expected dividend yield	1.00%
Expected stock volatility	31.59%
Estimated fair value of stock option	$5.63

Stockholders_Equity_Reconcilia

Stockholders' Equity - Reconciliation of Denominators used in Computation of Basic and Diluted Earnings Per Share (Details)	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Stockholders' Equity Note [Abstract]
Basic weighted average shares outstanding	296,842,771	296,237,956	296,755,815	295,964,359
Weighted shares assumed upon exercise of stock options	873,604	940,790	945,509	1,119,341
Diluted weighted average shares outstanding	297,716,375	297,178,746	297,701,324	297,083,700

Stockholders_Equity_Summary_of3

Stockholders' Equity - Summary of Anti-Dilutive Options Excluded (Details) (USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Stockholders' Equity Note [Abstract]
Options to purchase shares of common stock	1,313,261	1,578,804	1,263,599	735,675
Weighted average exercise price of options	$54	$49.43	$54	$54

Income_Taxes_Additional_Inform

Income Taxes - Additional Information (Detail) (USD $)	Sep. 30, 2013	Sep. 30, 2012
In Thousands, unless otherwise specified
Income Tax Disclosure [Abstract]
Liabilities recorded related to unrecognized tax benefits	$4,692	$4,254

Operating_Leases_Additional_In

Operating Leases - Additional Information (Detail) (USD $)	9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013
Leases, Operating [Abstract]
Term of non-cancellable pick-up truck leases (in years)	1 year
Renewal options for non-cancellable pick-up truck leases, maximum (in months)	72 months
Average pick-up truck lease term, minimum (in months)	28 months
Average pick-up truck lease term, maximum (in months)	36 months
Aggregate residual value guarantee	$48,709
Loss on disposal reserve	$43

Subsequent_Events_Additional_I

Subsequent Events - Additional Information (Details) (Subsequent Event [Member], USD $)	0 Months Ended
	Oct. 08, 2013
Subsequent Event [Member]
Subsequent Event [Line Items]
Dividend declared date	8-Oct-13
Dividend declared per share	$0.25