Former "American Idol" judge Randy Jackson's wife Erika filed for divorce on Sept. 26, Friday after 18 years of marriage.

The two have no prenup so Jackson's fortune, which he earned during their marriage, will be split in half, sources told TMZ.

Toward the end of his position as a judge in "American Idol" for 12 years before becoming a mentor on the television singing competition, Jackson reportedly earned an average of approximately $5 million each year and his estimated worth is $40 million.

While Jackson already earned some of his $40 million even before their marriage, his separate property reportedly has been commingled so it will be impossible to sort out.

Sources also told TMZ the two are in good terms and, in fact, still living together.

"It's not gonna be all Amber Rose and Wiz Khalifa," one source said referring to the musician couple who reportedly split because rapper Khalifa cheated on his wife.

On the other hand, the Jackson couple's divorce reportedly has nothing to do with infidelity.

"Randy and Erika had a plan (of how they would file) but at the end of the day she decided to file (on Sept. 26, Friday). Randy is bummed out. It's not the way he wanted it to happen or end," a source told People.

Citing irreconcilable differences in court documents she filed, Jackson's wife also seeks full physical custody and joint legal custody of their 17-year-old son Jordan, the same publication reported.

They also have a 19-year-old daughter named Zoe, who was not mentioned in the court documents.

Before Erika, the 58-year-old bassist, singer, record producer and entrepreneur was married to Elizabeth Jackson but they divorced in 1990. They have a daughter named Taylor.

Aside from serving as a judge on "American Idol," Jackson is also known for executive producing MTV's "America's Best Dance Crew."

He and his wife also ran the Randy and Erika Family Foundation, whose endeavors included a focus on dance and physical activity, the Los Angeles Sentinel has learned.

A rep for Jackson has yet to comment on the divorce.