Diane Lane and Josh Brolin
02/22/2013 AT 03:00 PM EST
There were likely no flowers or candy exchanged on Feb. 14 between Josh Brolin and soon-to-be ex-wife
Lane signed her divorce documents on Valentine's Day, documents filed in Los Angeles Superior Court reveal. Lane also cited Feb. 13 as the date of their official separation, although a source tells PEOPLE it was earlier than that.
"They've been separated for several months. This was a hard decision for both of them to make," says a source close to the couple of their split
. "The relationship just ran its course."
The pair, who married in a 2004 ceremony
at Brolin's central California ranch, were first introduced by the actor's stepmother, Barbra Streisand, at a party in 2002.
Brolin, 45, was recently arrested and held for public intoxication just before midnight on New Year's Eve 2013, but he was released without charge.