10:33 AM PST: The divorce documents cite "irreconcilable differences." Lane wants her name restored to Diane Lane -- it's currently Diane Lane Brolin.
Diane Lane is the one who threw in the towel ... we've learned she's the one who filed legal docs for divorce from Josh Brolin.
We found the legal docs, which were filed February 15 -- right after Valentine's Day -- in L.A. County Superior Court.
We know Lane claims she has been separated from Brolin for quite a while, although the legal date of separation on the docs is listed as February 13.
They definitely had issues in the past. Four months after they married in 2004, Brolin was arrested for spousal battery, but Lane recanted her story and charges were never filed.
He was also arrested for fighting in a bar in Louisiana in 2008. Drinking was involved. Interestingly, when he was arrested, he turned to his buddy, actor Jeffrey Wright, and said, "My wife is gonna be so happy." The charges were eventually dismissed.
And Brolin was arrested in Santa Monica this past New Year's Day for public intoxication.
Nonetheless ... a source connected with the couple tells TMZ ... "There were no dark issues between them. They still love and respect each other. This was a successful marriage that ran its course."