Contingencies	9 Months Ended
Sep. 30, 2018
Commitments and Contingencies Disclosure [Abstract]
COMMITMENTS AND CONTINGENCIES	Note 16. Contingencies Litigation Overview From time to time, the Company may be subject to legal proceedings and litigation arising in the ordinary course of business, including, but not limited to, inquiries, investigations, audits and other regulatory proceedings, such as described below. The Company records a loss provision when it believes it is both probable that a liability has been incurred and the amount can be reasonably estimated. Unless otherwise disclosed, the Company is unable to estimate the possible loss or range of loss for the legal proceeding described below. Except for the lawsuit described below, the Company believes that there are no claims or actions pending or threatened against it, the ultimate disposition of which would have a material adverse effect on it. Class Action and Shareholder Derivative Litigation On August 5, 2017, a lawsuit was filed in the U.S. District Court for the Southern District of Texas against the Company and two of its officers in Mona Abouzied v. Applied Optoelectronics, Inc., Chih-Hsiang (Thompson) Lin, and Stefan J. Murry, et al., Case No. 4:17-cv-02399. The complaint in this matter seeks class action status on behalf of the Company’s shareholders, alleging violations of Sections 10(b) and 20(a) of the Exchange Act against the Company, its chief executive officer, and its chief financial officer, arising out of its announcement on August 3, 2017 that “we see softer than expected demand for our 40G solutions with one of our large customers that will offset the sequential growth and increased demand we expect in 100G.” A second, related action was filed by Plaintiff Chad Ludwig on August 16, 2017 (Case No. 4:17-cv-02512) in the Southern District of Texas. The two cases were consolidated before Judge Vanessa D. Gilmore. On January 22, 2018, the court appointed Lawrence Rougier as Lead Plaintiff and Levi & Korinsky LLP as Lead Counsel. Lead Plaintiff filed an amended consolidated class action complaint on March 6, 2018. The amended complaint requests unspecified damages and other relief. The Company disputes the allegations and intends to vigorously contest the matter. The Company filed a motion to dismiss on April 4, 2018. Lead Plaintiff filed a response in opposition to the motion to dismiss on May 4, 2018, and briefing was completed on May 21, 2018. Further deadlines in this matter have been stayed until the court issues a decision on the pending motion to dismiss. On August 7, 2018, Plaintiff Lei Jin filed a purported derivative action on behalf of nominal defendant Applied Optoelectronics, Inc. in the U.S. District Court for the Southern District of Texas against the Company’s chief executive officer, chief financial officer and board of directors (Case No. 4:18-cv-02713). The allegations in the derivative complaint are substantially similar to those underlying the Abouzied securities class action. The parties have agreed to stay the derivative action until the court rules on the pending motion to dismiss in the Abouzied securities class action. The court signed the stay order on September 25, 2018. On October 1, 2018, a lawsuit was filed in the U.S. District Court for the Southern District of Texas against the Company and two of its officers in Gaurav Taneja v. Applied Optoelectronics, Inc., Thompson Lin, and Stefan Murry, Case No. 4:18-cv-03544. The complaint in this matter seeks class action status on behalf of the Company’s shareholders, alleging violations of Sections 10(b) and 20(a) of the Exchange Act against the Company, its chief executive officer, and its chief financial officer, arising out of its announcement on September 28, 2018 that it was revising its third quarter revenue guidance due to “an issue with a small percentage of 25G lasers within a specific customer environment.” A second, related action was filed by Plaintiff Davin Pokoik on October 10, 2018 (Case No. 4:18-cv-03722) in the Southern District of Texas. The Company disputes the allegations and intends to vigorously contest the matter.

Note 16. Contingencies

Litigation

Overview

From time to time, the Company may be subject to legal proceedings and litigation arising in the ordinary course of business, including, but not limited to, inquiries, investigations, audits and other regulatory proceedings, such as described below. The Company records a loss provision when it believes it is both probable that a liability has been incurred and the amount can be reasonably estimated. Unless otherwise disclosed, the Company is unable to estimate the possible loss or range of loss for the legal proceeding described below.

Except for the lawsuit described below, the Company believes that there are no claims or actions pending or threatened against it, the ultimate disposition of which would have a material adverse effect on it.

Class Action and Shareholder Derivative Litigation

On August 5, 2017, a lawsuit was filed in the U.S. District Court for the Southern District of Texas against the Company and two of its officers in Mona Abouzied v. Applied Optoelectronics, Inc., Chih-Hsiang (Thompson) Lin, and Stefan J. Murry, et al., Case No. 4:17-cv-02399. The complaint in this matter seeks class action status on behalf of the Company’s shareholders, alleging violations of Sections 10(b) and 20(a) of the Exchange Act against the Company, its chief executive officer, and its chief financial officer, arising out of its announcement on August 3, 2017 that “we see softer than expected demand for our 40G solutions with one of our large customers that will offset the sequential growth and increased demand we expect in 100G.” A second, related action was filed by Plaintiff Chad Ludwig on August 16, 2017 (Case No. 4:17-cv-02512) in the Southern District of Texas. The two cases were consolidated before Judge Vanessa D. Gilmore. On January 22, 2018, the court appointed Lawrence Rougier as Lead Plaintiff and Levi & Korinsky LLP as Lead Counsel. Lead Plaintiff filed an amended consolidated class action complaint on March 6, 2018. The amended complaint requests unspecified damages and other relief. The Company disputes the allegations and intends to vigorously contest the matter. The Company filed a motion to dismiss on April 4, 2018. Lead Plaintiff filed a response in opposition to the motion to dismiss on May 4, 2018, and briefing was completed on May 21, 2018. Further deadlines in this matter have been stayed until the court issues a decision on the pending motion to dismiss.

On August 7, 2018, Plaintiff Lei Jin filed a purported derivative action on behalf of nominal defendant Applied Optoelectronics, Inc. in the U.S. District Court for the Southern District of Texas against the Company’s chief executive officer, chief financial officer and board of directors (Case No. 4:18-cv-02713). The allegations in the derivative complaint are substantially similar to those underlying the Abouzied securities class action. The parties have agreed to stay the derivative action until the court rules on the pending motion to dismiss in the Abouzied securities class action. The court signed the stay order on September 25, 2018.

On October 1, 2018, a lawsuit was filed in the U.S. District Court for the Southern District of Texas against the Company and two of its officers in Gaurav Taneja v. Applied Optoelectronics, Inc., Thompson Lin, and Stefan Murry, Case No. 4:18-cv-03544. The complaint in this matter seeks class action status on behalf of the Company’s shareholders, alleging violations of Sections 10(b) and 20(a) of the Exchange Act against the Company, its chief executive officer, and its chief financial officer, arising out of its announcement on September 28, 2018 that it was revising its third quarter revenue guidance due to “an issue with a small percentage of 25G lasers within a specific customer environment.” A second, related action was filed by Plaintiff Davin Pokoik on October 10, 2018 (Case No. 4:18-cv-03722) in the Southern District of Texas. The Company disputes the allegations and intends to vigorously contest the matter.