I work for TeamHealth at my primary job site.
I have not encountered any pushback with respect to extra hours.
When I adjust my hours, I write in the "notes" field something akin to: "Stayed late for [critical care/admission, volume surge/etc]."
We also have 1 doc that is habitually 20 mins late because "California time, brahh", so I document that I'm here late if there's no overlap.
That being said; don't abuse this privilege.
EmCare freaked out on me at my old job site simply for staying to do all my charts, and declared that "all charting must be done within the scheduled shift".
Then, door-to-doc times creeped up across the board, and they bitched about that.
Seeing as how they put us in an impossible situation, our oldest doc freaked out on them and called them out on it.
He retired from clinical practice not long after that, and became an administrator.