'Black-ish' star Anthony Anderson's wife Alvina has filed for divorce citing irreconcilable differences after 20 years together. The Black-ish actor's spouse Alvina has cited irreconcilable differences in court documents obtained by TMZ.The 45-year-old star, who was nominated for an Emmy last weekend for his work on the sitcom, married his wife in 1995 and the couple have two children together, Kira, 19, and 15-year-old Nathan.Alvina is reportedly seeking joint legal custody and primary physical custody of Nathan, as well as spousal support from her famous husband.According to the court documents, the couple separated in April 2014.Anderson's representative told E! News: "Yes, the divorce papers are public record and they have been separated for some time now."The actor has recently enjoyed success on US sitcom Black-ish, which is currently in its second season.The show follows the comedic highs and lows of an African-American family and also stars Laurence Fishburne as Anderson's father.The comedian recently revealed that he'd love to see United States president Barack Obama make an appearance on the show.He said: "We're petitioning to get President Obama on the show. They watch the show. They love it. We know them so we've been dealing with them and their people and hopefully they'll say yes."..