Again, you are correct, your link suggests just what you are writing, unfortunately it is somewhat absurd the way it conflates assets and liabilities.

http://ballotpedia.org/Net_worth_of_United_States_Senators_a... lists median net worth over a million\

http://www.opensecrets.org/news/2014/01/millionaires-club-fo... also puts median net worth over 1 million

http://time.com/373/congress-is-now-mostly-a-millionaires-cl... also lists median net worth over a million

http://money.cnn.com/2015/01/12/news/economy/congress-wealth... also puts median net worth above 1 million

http://www.upi.com/Top_News/US/2015/01/13/Congress-worth-43B... also puts median net worth over a million