DETROIT -- Monty Williams is taking over the Detroit Pistons.

The team said Friday it reached an agreement with Williams to fill its coaching vacancy. Terms of the deal were not announced, but sources told ESPN's Adrian Wojnarowski Williams agreed to a six-year, $78.5 million contract. It is the largest coaching deal in NBA history.

"After spending some time with Monty, it's clear that he's found a unique balance between achieving victory at the highest level while at the same time nurturing a culture of growth, development and inspiration," Pistons owner Tom Gores said. "I'm beyond excited. This is a huge win for us."

The 51-year-old Williams was fired by Phoenix on May 13, two years after reaching the NBA Finals and a year after he won the league's coach of the year honors.

Williams won 63% of his games over four regular seasons with the Suns, but they were eliminated in the Western Conference semifinals two years in a row after losing to Milwaukee in the 2021 NBA Finals.

Williams will be formally introduced at a news conference in Detroit next week. He said he made the decision to sign on with the Pistons after a series of conversations with Gores, general manager Troy Weaver and other Pistons executives.

"A week ago, I was not sure what the future would hold," Williams said in the team's release. "But, after talking with Tom and Troy, I was excited hearing their vision for the Pistons going forward. They had a thoughtful plan and I am so appreciative of the emphasis they placed on the personal side of this business. They showed tremendous consideration for me and my family throughout this process."

Detroit won an NBA-low 17 games last season, and Dwane Casey stepped down as coach with one year left on his contract to take a role in the front office.

The Pistons did not have good fortune in the draft lottery, landing the No. 5 pick overall for the second straight year and missing out on an opportunity to draft 7-foot-5 French pro Victor Wembanyama, 19, who is expected to be the first overall pick of the San Antonio Spurs.

Detroit, a three-time NBA champion, has earned a spot in the playoffs just twice in 14 years. The Pistons have not won a postseason game since 2008, when they advanced to the Eastern Conference finals for the sixth straight time during a remarkable run that included winning the 2004 NBA title and falling a game short of repeating as champions.

Jaden Ivey and Jalen Duren, the No. 5 and No. 13 pick overall last summer, did provide hope for the future with their play last season. Cade Cunningham, the No. 1 pick overall in 2021, had his second season cut short by shin surgery.

Williams is 367-336 in nine seasons as an NBA head coach with a 29-27 postseason record. He had a five-year stint with the New Orleans Pelicans, who fired him in 2015 with a 173-221 record and two playoff appearances.

"Monty represented the ideal prototype for our young team, but we didn't expect him to be available," Weaver said in the release. "When he suddenly became available, we jumped at the opportunity to speak with him. That doesn't mean the others in our process were not strong candidates. They were. But Monty is the prototype."

The Associated Press contributed to this report.