Litigation	9 Months Ended
Sep. 30, 2016
Commitments and Contingencies Disclosure [Abstract]
Litigation	Note 6 - 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, Michael L. Elich, BBSI’s Chief Executive Officer, and James D. Miller, BBSI’s then Chief Financial Officer. The action purported to be a class action brought on behalf of all BBSI shareholders alleging violations of the federal securities laws. The claims arose from the decline in the market price for BBSI common stock following announcement of a charge for increased workers’ compensation reserves expense. The lawsuit sought compensatory damages, 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 named the same defendants as the Arciaga case and asserted 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 named the same defendants as the Arciaga and Carnes cases and asserted 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 consolidated cases were recaptioned as In re Barrett Business Services Securities Litigation. The court also appointed the Painters & Allied Trades District Council No. 35 Pension and Annuity Funds as the lead plaintiff. On March 21, 2016, before the court had ruled on the defendants’ motion to dismiss the plaintiffs’ first amended consolidated complaint, the plaintiffs filed a second amended consolidated complaint, naming the same defendants. The second amended consolidated complaint dropped certain allegations from the first amended complaint and added new allegations relating to disclosures in BBSI’s Current Report on Form 8-K filed on March 9, 2016. The defendants filed a motion to dismiss the second amended consolidated complaint on May 23, 2016. On October 26, 2016, before the court ruled on the motion to dismiss, the parties entered into a Stipulation and Agreement of Settlement dated as of October 26, 2016 (the “Settlement”), to settle the litigation. The settlement class includes all persons and entities who purchased or otherwise acquired BBSI common stock in the period beginning February 12, 2013, through March 9, 2016, and were damaged thereby, with certain exclusions. The Settlement is intended to fully, finally and forever compromise, settle, release, resolve, and dismiss with prejudice the purported class action and all claims asserted therein against the named defendants. In the Settlement, the defendants have denied all allegations of wrongdoing and the plaintiffs have not conceded any infirmities in their positions. The Settlement calls for the payment in cash of $12.0 million (the “Settlement Fund”) into escrow by November 29, 2016, which is 15 business days after the court entered an order preliminarily approving the Settlement. Of this amount, approximately $8.7 million will be paid by BBSI’s insurance carriers and approximately $3.3 million will be paid by BBSI. The amount to be paid by BBSI has been accrued at September 30, 2016 and is included in other accrued liabilities in our condensed consolidated balance sheet. The fees of counsel for the plaintiffs will be paid out of the Settlement Fund following approval by the court. The Settlement is subject to approval by the court and to other customary terms and conditions, including the right of BBSI to terminate the Settlement under specified circumstances. All potential class members will be notified of the Settlement in November 2016. The court has scheduled a hearing for February 22, 2017, to consider final approval of the Settlement. If the Settlement is not approved by the court, or is otherwise terminated before it is finalized, BBSI is unable to predict the final outcome of the litigation or to estimate its effect on BBSI, which may be material and adverse. BBSI received a subpoena from the San Francisco office of the Division of Enforcement of the Securities and Exchange Commission (the “SEC”) in May 2015 in connection with the SEC’s investigation of BBSI’s accounting practices with regard to its workers’ compensation reserves. In April 2016, the SEC issued a second subpoena to BBSI for documents relating to the disclosures made by BBSI following Mr. Miller’s termination. BBSI was also advised by the United States Department of Justice in mid-June 2016 that it has commenced an investigation. BBSI is cooperating fully with the investigations. On June 17, 2015, Daniel Salinas (“Salinas”) filed a shareholder derivative lawsuit against BBSI and certain of its officers and directors in the Circuit Court for Baltimore City, Maryland. The complaint alleges breaches of fiduciary duty, unjust enrichment and other violations of law and seeks recovery of various damages, including the costs and expenses incurred in connection with BBSI’s reserve strengthening process, reserve study and consultants, the cost of stock repurchases by BBSI in October 2014, compensation paid to BBSI’s officers, and costs of negotiating BBSI’s credit facility with its principal lender, as well as the proceeds of sales of stock by certain of BBSI’s officers and directors during 2013 and 2014. On September 28, 2015, BBSI and the individual defendants filed motions to dismiss the derivative suit and a motion to stay pending resolution of In re Barrett Business Services Securities Litigation. On December 4, 2015, Salinas filed an opposition to each motion. On January 27, 2016, the defendants filed a reply to the opposition brief. On February 11, 2016, Judge Michel Pierson heard oral argument on the motions. A decision has not been issued. Management is unable to estimate the probability, or the potential range of loss arising from the legal actions described above. BBSI 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 other currently pending or threatened actions is not expected to materially affect BBSI’s consolidated financial position or results of operations.

Note 6 - 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, Michael L. Elich, BBSI’s Chief Executive Officer, and James D. Miller, BBSI’s then Chief Financial Officer. The action purported to be a class action brought on behalf of all BBSI shareholders alleging violations of the federal securities laws. The claims arose from the decline in the market price for BBSI common stock following announcement of a charge for increased workers’ compensation reserves expense. The lawsuit sought compensatory damages, 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 named the same defendants as the Arciaga case and asserted 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 named the same defendants as the Arciaga and Carnes cases and asserted 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 consolidated cases were recaptioned as In re Barrett Business Services Securities Litigation. The court also appointed the Painters & Allied Trades District Council No. 35 Pension and Annuity Funds as the lead plaintiff.

On March 21, 2016, before the court had ruled on the defendants’ motion to dismiss the plaintiffs’ first amended consolidated complaint, the plaintiffs filed a second amended consolidated complaint, naming the same defendants. The second amended consolidated complaint dropped certain allegations from the first amended complaint and added new allegations relating to disclosures in BBSI’s Current Report on Form 8-K filed on March 9, 2016. The defendants filed a motion to dismiss the second amended consolidated complaint on May 23, 2016.

On October 26, 2016, before the court ruled on the motion to dismiss, the parties entered into a Stipulation and Agreement of Settlement dated as of October 26, 2016 (the “Settlement”), to settle the litigation. The settlement class includes all persons and entities who purchased or otherwise acquired BBSI common stock in the period beginning February 12, 2013, through March 9, 2016, and were damaged thereby, with certain exclusions.

The Settlement is intended to fully, finally and forever compromise, settle, release, resolve, and dismiss with prejudice the purported class action and all claims asserted therein against the named defendants. In the Settlement, the defendants have denied all allegations of wrongdoing and the plaintiffs have not conceded any infirmities in their positions.

The Settlement calls for the payment in cash of $12.0 million (the “Settlement Fund”) into escrow by November 29, 2016, which is 15 business days after the court entered an order preliminarily approving the Settlement. Of this amount, approximately $8.7 million will be paid by BBSI’s insurance carriers and approximately $3.3 million will be paid by BBSI. The amount to be paid by BBSI has been accrued at September 30, 2016 and is included in other accrued liabilities in our condensed consolidated balance sheet. The fees of counsel for the plaintiffs will be paid out of the Settlement Fund following approval by the court.

The Settlement is subject to approval by the court and to other customary terms and conditions, including the right of BBSI to terminate the Settlement under specified circumstances. All potential class members will be notified of the Settlement in November 2016. The court has scheduled a hearing for February 22, 2017, to consider final approval of the Settlement. If the Settlement is not approved by the court, or is otherwise terminated before it is finalized, BBSI is unable to predict the final outcome of the litigation or to estimate its effect on BBSI, which may be material and adverse.

BBSI received a subpoena from the San Francisco office of the Division of Enforcement of the Securities and Exchange Commission (the “SEC”) in May 2015 in connection with the SEC’s investigation of BBSI’s accounting practices with regard to its workers’ compensation reserves. In April 2016, the SEC issued a second subpoena to BBSI for documents relating to the disclosures made by BBSI following Mr. Miller’s termination. BBSI was also advised by the United States Department of Justice in mid-June 2016 that it has commenced an investigation. BBSI is cooperating fully with the investigations.

On June 17, 2015, Daniel Salinas (“Salinas”) filed a shareholder derivative lawsuit against BBSI and certain of its officers and directors in the Circuit Court for Baltimore City, Maryland. The complaint alleges breaches of fiduciary duty, unjust enrichment and other violations of law and seeks recovery of various damages, including the costs and expenses incurred in connection with BBSI’s reserve strengthening process, reserve study and consultants, the cost of stock repurchases by BBSI in October 2014, compensation paid to BBSI’s officers, and costs of negotiating BBSI’s credit facility with its principal lender, as well as the proceeds of sales of stock by certain of BBSI’s officers and directors during 2013 and 2014. On September 28, 2015, BBSI and the individual defendants filed motions to dismiss the derivative suit and a motion to stay pending resolution of In re Barrett Business Services Securities Litigation. On December 4, 2015, Salinas filed an opposition to each motion. On January 27, 2016, the defendants filed a reply to the opposition brief. On February 11, 2016, Judge Michel Pierson heard oral argument on the motions. A decision has not been issued.

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

BBSI 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 other currently pending or threatened actions is not expected to materially affect BBSI’s consolidated financial position or results of operations.