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Aggregate dividends declared during the period for each share of common stock outstanding.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 04

-Article 3

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 505

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-Section S99

-Paragraph 1

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Date the declared dividend will be paid, in CCYY-MM-DD format.

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-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 50

-Paragraph 3

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Date the dividend to be paid was declared, in CCYY-MM-DD format.

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Date the holder must own the stock to be entitled to the dividend, in CCYY-MM-DD format.

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No definition available.

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- Definition

Unrecognized cost of unvested share-based compensation awards.

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-Publisher FASB

-Name Accounting Standards Codification

-Topic 718

-SubTopic 10

-Section 50

-Paragraph 2

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Weighted average period over which unrecognized compensation is expected to be recognized for equity-based compensation plans, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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The aggregate amount of noncash, equity-based employee remuneration. This may include the value of stock or unit options, amortization of restricted stock or units, and adjustment for officers' compensation. As noncash, this element is an add back when calculating net cash generated by operating activities using the indirect method.

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Period which an employee's right to exercise an award is no longer contingent on satisfaction of either a service condition, market condition or a performance condition, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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Period from grant date that an equity-based award expires, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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Stockholders' Equity - Additional Information (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		0 Months Ended
	Mar. 31, 2015	Mar. 31, 2014	Apr. 13, 2015
Schedule of Shareholders' Equity [Line Items]
Options vesting and exercisable period, maximum	8 years
Options termination period	9 years
Total stock-based compensation expense for the Fastenal stock option plan	$ 1,620us-gaap_ShareBasedCompensation	$ 1,380us-gaap_ShareBasedCompensation
Total unrecognized stock-based compensation expense	$ 14,440
Weighted average period over which total unrecognized stock-based compensation expense will be recognized	4 years 6 months 7 days
Subsequent Event [Member]
Schedule of Shareholders' Equity [Line Items]
Dividend declared date			Apr. 13, 2015
Dividend declared per share			$ 0.28
Dividend payment date			May 26, 2015
Dividend payable record date			Apr. 28, 2015