What type of documentation needed to confirm receipt of exh pension adjustment money?

[rollercoaster]

My ex and I didn't settle the pension adjustment at time of separation and agreed to do it in the months following. My exh and I both have company pensions and have determined their value. To equalize, my exh owes me money.

What kind of document do I need to acknowledge he released the funds to me and I have received them? Can it be as simple as writing a detailed receipt, or should it be a formal letter drafted by a lawyer?