Stockholders' equity

12 Months Ended

Dec. 31, 2020

Equity [Abstract]

Stockholders' equity

Stockholders' Equity

Authorized shares

We are authorized to issue two classes of stock, common stock and preferred stock. On June 9, 2015, the board of directors amended and restated our Amended and Restated Certificate of Incorporation, effective upon the closing of our IPO on July 1, 2015, and authorized us to issue up to 300,000,000 shares of common stock and 10,000,000 shares of undesignated preferred stock.

Common and Preferred Stock

As of December 31, 2020 and 2019, there were 49,630,773 and 48,700,963 shares of common stock issued, and 49,483,620 and 48,700,713 shares of common stock outstanding, respectively. As of December 31, 2020 and 2019, there were no preferred shares issued and outstanding. Each outstanding share of common stock is entitled to one vote per share.

Stock Repurchase Programs

On November 29, 2018, our board of directors authorized a stock repurchase program, under which we were authorized to purchase up to an aggregate of $75.0 million of our outstanding common stock during the two-year period ended November 29, 2020. On December 3, 2020, our board of directors authorized another stock repurchase program, under which we are authorized to purchase up to an aggregate of $100.0 million of our outstanding common stock during the three-year period ending December 3, 2023. During the year ended December 31, 2020, we repurchased 147,153 shares of our common stock under the program that expired on November 29, 2020. No shares were purchased under these programs during the years ended 2019 and 2018.