This dude is paid!
This dude has to be filthy rich. He's been in Family Guy for 12 years now, and as we all know from the Simpson's Clan, you're paid for long running animated shows like that. The dude also has the success of Robot Chicken, voicing several big animated movies, the occasional comedy, the small parts in the Austin Powers movies, etc.
Dude probably pays someone to go to the bathroom for him!