David Kohl/Associated Press

Following a breakout 2015 campaign, the Cincinnati Bengals signed safety Shawn Williams to a contract extension Tuesday.

The team announced it is a four-year deal but did not reveal financial terms of the agreement. However, NFL Network's Ian Rapoport, citing a source, reported that Williams' extension is worth $19.5 million with $4 million guaranteed.

Williams, 25, appeared in all 16 games last season, registering 32 tackles and the first two interceptions of his career in four starts.

Cincinnati decided against re-signing longtime starter Reggie Nelson, which means Williams will assume that role with Nelson now part of the Oakland Raiders roster.

Per Paul Dehner Jr. of the Cincinnati Enquirer, the Bengals have long viewed Williams as a starting-caliber player:

The fourth-year defensive back was a third-round pick out of Georgia in 2013, and after playing sparingly in his first two seasons, he showed flashes when given opportunities in 2015.

Video Play Button Videos you might like

Cincinnati re-signed safety George Iloka to a long-term contract this offseason as well, which means the back end of head coach Marvin Lewis' defense could be set in stone for years to come.

The Bengals ranked third in the NFL last season with 21 interceptions, and if the progress Williams made translates to 2016, they could move even higher up that list during the upcoming season.

Follow @MikeChiari on Twitter.