"Free"? He gets a fat pension ~ but that's because Congresscritters get double credit for every year service. You take 60 years service time he maxed out his CSRS at 80% of his high three, but if he transferred to FERS in 1987/88 ~ he'd get another 22% on top of that, or 102% of high three.
Just another day in Congress.
Where he gets the big bucks is working for a lobbyist.