The numbers above are the base estimates; each is "at least" as rich as stated above, because as you point out -- and the article points out -- the disclosures are listed in ranges. If you don't believe the article, try CNN:
John Kerry, D-Massachusetts: $163,626,399
Herb Kohl, D-Wisconsin: $111,015,016
John Rockefeller, D -West Virginia: $81,648,018
Jon Corzine, D-New Jersey: $71,035,025
Dianne Feinstein, D-California: $26,377,109
Peter Fitzgerald, R-Illinois: $26,132,013
Frank Lautenberg, D-New Jersey $17,789,018
Bill Frist, R-Tennessee: $15,108,042
John Edwards, D-North Carolina: $12,844,029
Edward Kennedy, D-Massachusetts: $9,905,009
Jeff Bingaman, D-New Mexico: $7,981,015
Bob Graham, D-Florida: $7,691,052
Richard Shelby, R-Alabama: $7,085,012
Gordon Smith, R-Oregon: $6,429,011
Lincoln Chafee, R-Rhode Island: $6,296,010
Ben Nelson, D-Nebraska: $6,267,028
Lamar Alexander, R-Tennessee: $4,823,018
Mike DeWine, R-Ohio: $4,308,093
Mark Dayton, D-Minnesota: $3,974,037
Ben Campbell, R-Colorado: $3,165,007
Chuck Hagel, R-Nebraska: $2,963,013
Olympia Snowe, R-Maine: $2,955,037
James Talent, R-Missouri: $2,843,031
Arlen Specter, R-Pennsylvania: $2,045,016
Judd Gregg, R-New Hampshire: $1,916,026
John McCain, R-Arizona: $1,838,010
James Inhofe, R-Oklahoma: $1,570,043
John Warner, R-Virginia: $1,545,039
Kay Bailey Hutchison, R - Texas: $1,513,046
Mitch McConnell, R-Kentucky: $1,511,017
Harry Reid, D-Nevada: $1,500,040
Sam Brownback, R-Kansas: $1,491,018
Thomas Carper, D-Delaware: $1,482,017
Ted Stevens, R-Alaska: $1,417,013
Maria Cantwell, D-Washington: $1,264,999
Barbara Boxer, D-California: $1,172,003
Orrin Hatch, R-Utah: $1,086,023
Mary Landrieu, D-Louisiana: $1,080,014
Bill Nelson, D-Florida: $1,073,014
Charles Grassley, R-Iowa: $1,016,024
*These figures are base estimates provided by senators on their financial disclosure forms.
http://www.cnn.com/2003/ALLPOLITICS/06/13/senators.finances/