Litigation	3 Months Ended
Mar. 31, 2015
Commitments and Contingencies Disclosure [Abstract]
Litigation	Note 8 - Litigation On November 6, 2014, plaintiffs in Michael Arciaga, et al. v. Barrett Business Services, Inc., et al., filed an action in the United States District Court for the Western District of Washington against BBSI and Michael L. Elich and James D. Miller, BBSI’s Chief Executive Officer and Chief Financial Officer, respectively. The action purports to be a class action brought on behalf of all Company shareholders alleging violations of the federal securities laws. The claims arise from the decline in the market price for BBSI common stock following announcement of a charge for increased workers compensation reserves expense. The lawsuit seeks compensatory damages (in an amount to be determined at trial), plus interest, and costs and expenses (including attorney fees and expert fees). On November 13, 2014, a second purported shareholder class action was filed in the United States District Court for the Western District of Washington, entitled Christopher P. Carnes, et al. v. Barrett Business Services, Inc., et al. The Carnes complaint names the same defendants as the Arciaga case and asserts similar claims for relief. Similarly, on November 17, 2014, a third purported shareholder class action was filed in the United States District Court for the Western District of Washington, entitled Shiva Stein, et al. v. Barrett Business Services, Inc., et al. The Stein complaint names the same defendants as the Arciaga and Carnes cases and asserts similar claims for relief. On February 25, 2015, the court ordered consolidation of the three cases, and any new or other cases involving the same subject matter, into a single action for pretrial purposes. The court also appointed the Painters & Allied Trades District Council No. 35 Pension and Annuity Funds as the lead plaintiff. On April 29, 2015, the plaintiffs in the class action filed a consolidated amended complaint that asserts the same legal claims as the original lawsuits. BBSI intends to file a motion to dismiss the complaint no later than June 12, 2015. Discovery has not been undertaken as it is automatically stayed under the federal Private Securities Litigation Reform Act. On February 27, 2015, BBSI received a letter from counsel for an alleged stockholder accusing each of the Company’s directors and officers with having breached his fiduciary duties of loyalty and good faith based on the same facts as those alleged in the three lawsuits described above and alleging that the Company has sustained and continues to sustain damages, including the costs and expenses incurred in connection with the Company’s reserve strengthening process, reserve study and consultants, the cost of stock repurchases in October 2014, compensation paid to the Company’s officers, and costs of negotiating the Company’s credit facility with its principal lender. The letter demands that BBSI’s Board of Directors take action against each of the Company’s officers and directors to recover these damages and the proceeds of sales of stock by the officers and directors during 2013 and 2014. The letter states that if the Board does not take these actions within a reasonable period, the stockholder will commence a shareholder derivative action on behalf of the Company. With the assistance of outside counsel, the Board conducted an investigation of the allegations made by the stockholder and responded on May 4, 2015, that it found no basis for taking legal action against any of BBSI’s officers or directors. Management is unable to estimate the probability, or the potential range, of loss arising from these legal actions. The Company is subject to other legal proceedings and claims, which arise in the ordinary course of our business. In the opinion of management, the amount of ultimate liability with respect to currently pending or threatened actions is not expected to materially affect the consolidated financial position or results of operations of the Company.

Note 8 - Litigation

On November 6, 2014, plaintiffs in Michael Arciaga, et al. v. Barrett Business Services, Inc., et al., filed an action in the United States District Court for the Western District of Washington against BBSI and Michael L. Elich and James D. Miller, BBSI’s Chief Executive Officer and Chief Financial Officer, respectively. The action purports to be a class action brought on behalf of all Company shareholders alleging violations of the federal securities laws. The claims arise from the decline in the market price for BBSI common stock following announcement of a charge for increased workers compensation reserves expense. The lawsuit seeks compensatory damages (in an amount to be determined at trial), plus interest, and costs and expenses (including attorney fees and expert fees).

On November 13, 2014, a second purported shareholder class action was filed in the United States District Court for the Western District of Washington, entitled Christopher P. Carnes, et al. v. Barrett Business Services, Inc., et al. The Carnes complaint names the same defendants as the Arciaga case and asserts similar claims for relief.

Similarly, on November 17, 2014, a third purported shareholder class action was filed in the United States District Court for the Western District of Washington, entitled Shiva Stein, et al. v. Barrett Business Services, Inc., et al. The Stein complaint names the same defendants as the Arciaga and Carnes cases and asserts similar claims for relief.

On February 25, 2015, the court ordered consolidation of the three cases, and any new or other cases involving the same subject matter, into a single action for pretrial purposes. The court also appointed the Painters & Allied Trades District Council No. 35 Pension and Annuity Funds as the lead plaintiff.

On April 29, 2015, the plaintiffs in the class action filed a consolidated amended complaint that asserts the same legal claims as the original lawsuits. BBSI intends to file a motion to dismiss the complaint no later than June 12, 2015. Discovery has not been undertaken as it is automatically stayed under the federal Private Securities Litigation Reform Act.

On February 27, 2015, BBSI received a letter from counsel for an alleged stockholder accusing each of the Company’s directors and officers with having breached his fiduciary duties of loyalty and good faith based on the same facts as those alleged in the three lawsuits described above and alleging that the Company has sustained and continues to sustain damages, including the costs and expenses incurred in connection with the Company’s reserve strengthening process, reserve study and consultants, the cost of stock repurchases in October 2014, compensation paid to the Company’s officers, and costs of negotiating the Company’s credit facility with its principal lender. The letter demands that BBSI’s Board of Directors take action against each of the Company’s officers and directors to recover these damages and the proceeds of sales of stock by the officers and directors during 2013 and 2014. The letter states that if the Board does not take these actions within a reasonable period, the stockholder will commence a shareholder derivative action on behalf of the Company. With the assistance of outside counsel, the Board conducted an investigation of the allegations made by the stockholder and responded on May 4, 2015, that it found no basis for taking legal action against any of BBSI’s officers or directors.

Management is unable to estimate the probability, or the potential range, of loss arising from these legal actions.

The Company is subject to other legal proceedings and claims, which arise in the ordinary course of our business. In the opinion of management, the amount of ultimate liability with respect to currently pending or threatened actions is not expected to materially affect the consolidated financial position or results of operations of the Company.