Casey Affleck Discloses Income in Divorce

Casey Affleck is a successful actor, but it's a little surprising how much he rakes in in the movie biz.

According to new docs, obtained by TMZ, Affleck pulls in $400,000 a year ... we're guessing big brother Ben rakes in exponentially more.

The divorce docs also reveal child support payments for the 2 kids he shares with ex-wife Summer Phoenix. He's paying her $4,000 a month. He's also going to be paying private school tuition for the kids for the next 2 years.

As for spousal support ... he's not paying her anything.