MIAMI -- Ryan Tannehill stopped the Miami Dolphins' revolving door at quarterback, and on Monday they rewarded him.

Tannehill signed a $77.7 million, four-year extension that keeps him under contract through 2020. He's the first quarterback to receive an extension from the 2012 draft class that also included the Colts' Andrew Luck, the Redskins' Robert Griffin III and the Seahawks' Russell Wilson.

"We are thrilled that we were able to sign Ryan to an extension," said Mike Tannenbaum, executive vice-president of football operations. "He is an ascending talent, a team leader and checks all of the boxes you are looking for at the position."

When Tannehill joined the lineup as a rookie, he was the Dolphins' 17th starting quarterback since 2000. With the extension, he becomes their first franchise QB since Dan Marino.

"You look back at all of the great players over the years, and most of them spent a significant amount of time in one place," Tannehill told the team's website. "I'm blessed to be in this position to be here for the next six years."

Last month the Dolphins exercised their fifth-year, $16.2 million option for 2016 on Tannehill's rookie contract. The eighth overall pick of the 2012 draft, Tannehill has started every game in his first three seasons and improved each year, although he has yet to lead Miami to a playoff berth.

Last season he threw for 4,045 yards with 27 touchdowns, and his passer rating was 92.8. All of those figures were career highs.

"Signing Ryan to this deal is important to our franchise," general manager Dennis Hickey said. "He is a proven quarterback in this league that combines a talented skillset with work ethic, passion, toughness and a team-first mentality. We are committed and believe in Ryan as our quarterback for the long term, and we are excited to be able to sign him to this extension."

The 2016 salary will be a big increase for Tannehill after making a total of $12.7 million in the first four years of his contract. He said the extension represents a vote of confidence from the Dolphins and owner Stephen Ross.

"I'm excited that Stephen Ross and the rest of the organization put it out there that they do have faith in me," he said. "I'm excited to be part of the team for the next few years."