It seems, from opensecrets.org's review of his financial disclosure forms, that McConnell's wealth has jumped substantially in the last few years.
Back in 2005, McConnell's net worth was somewhere between $1,645,032 and $4,278,999, ranking him the 38th richest Senator.
After four years when the stock market has flatlined, McConnell now has a net worth between $7,102,036 and $32,756,000, and he's now the 12th wealthiest Senator.
Pretty good, for a guy who has evidently NEVER had a private sector job.