Contingencies	9 Months Ended
Sep. 30, 2012
Commitments and Contingencies Disclosure [Abstract]
Contingencies	(6) Contingencies In early February 2010, we received a letter from a California fastener supplier dated January 26, 2010. This letter threatened to sue us for an alleged violation of an exclusive distribution arrangement this supplier believes exists between our organizations. In addition to the letter, this supplier provided a press release and a video regarding the claim which they threatened to make public unless we agreed to mediation of the claim. Shortly after receipt of this letter, we performed a preliminary internal review to understand (1) who this supplier was and (2) the nature of our relationship with this supplier. Based on that review, we determined (1) this supplier manufactures a niche type of fastener and (2) the total volume of purchases by us, from all suppliers, over the purported term of the alleged exclusivity arrangement of this niche type of fastener did not exceed $1 million. Following completion of our preliminary internal review, we requested additional information and documentation from the supplier. The supplier’s response failed to provide the requested information and documentation. By letter dated February 26, 2010, we quantified for the supplier our total volume of purchases as discussed above and informed the supplier that we believed their claim was grossly exaggerated and completely unsupported. We have not received any direct response to our February 26, 2010 letter. On May 3, 2010, this supplier filed suit in Arkansas federal court alleging damages. In response, we filed a motion to dismiss. This motion to dismiss was denied on August 16, 2010. We subsequently filed two motions for summary judgment. The first summary judgment motion was partially denied. On August 24, 2011, the court issued an order granting Fastenal’s second motion for summary judgment in its entirety, the supplier appealed this order on September 8, 2011. On December 16, 2011, the court issued an order granting, in part, Fastenal’s request to recover on its Bill of Costs and Petition for Attorney’s Fees from this supplier, the supplier appealed this order on January 9, 2012. On August 21, 2012, the appeals court issued a ruling affirming the August 24, 2011 and December 16, 2011 orders. The appeals court filed a Mandate order on September 13, 2012 to effectively conclude these proceedings. While we are not required to disclose this matter under the rules of the Securities and Exchange Commission (‘SEC’), we initially disclosed the existence of this threat in February 2010 (in our 2009 annual report on Form 10-K) as we believed our disclosure was prudent due to the alleged amount ($180 million) of the claim and the threat to make these allegations public. The disclosure of these legal proceedings will be omitted from future filings.

(6) Contingencies

In early February 2010, we received a letter from a California fastener supplier dated January 26, 2010. This letter threatened to sue us for an alleged violation of an exclusive distribution arrangement this supplier believes exists between our organizations. In addition to the letter, this supplier provided a press release and a video regarding the claim which they threatened to make public unless we agreed to mediation of the claim. Shortly after receipt of this letter, we performed a preliminary internal review to understand (1) who this supplier was and (2) the nature of our relationship with this supplier. Based on that review, we determined (1) this supplier manufactures a niche type of fastener and (2) the total volume of purchases by us, from all suppliers, over the purported term of the alleged exclusivity arrangement of this niche type of fastener did not exceed $1 million. Following completion of our preliminary internal review, we requested additional information and documentation from the supplier. The supplier’s response failed to provide the requested information and documentation. By letter dated February 26, 2010, we quantified for the supplier our total volume of purchases as discussed above and informed the supplier that we believed their claim was grossly exaggerated and completely unsupported. We have not received any direct response to our February 26, 2010 letter. On May 3, 2010, this supplier filed suit in Arkansas federal court alleging damages. In response, we filed a motion to dismiss. This motion to dismiss was denied on August 16, 2010. We subsequently filed two motions for summary judgment. The first summary judgment motion was partially denied.

On August 24, 2011, the court issued an order granting Fastenal’s second motion for summary judgment in its entirety, the supplier appealed this order on September 8, 2011. On December 16, 2011, the court issued an order granting, in part, Fastenal’s request to recover on its Bill of Costs and Petition for Attorney’s Fees from this supplier, the supplier appealed this order on January 9, 2012. On August 21, 2012, the appeals court issued a ruling affirming the August 24, 2011 and December 16, 2011 orders. The appeals court filed a Mandate order on September 13, 2012 to effectively conclude these proceedings. While we are not required to disclose this matter under the rules of the Securities and Exchange Commission (‘SEC’), we initially disclosed the existence of this threat in February 2010 (in our 2009 annual report on Form 10-K) as we believed our disclosure was prudent due to the alleged amount ($180 million) of the claim and the threat to make these allegations public. The disclosure of these legal proceedings will be omitted from future filings.