Sorting currency column

I am having problems sorting the "Amount" column... its sorting by the first integer instead of the entire value

http://lifescienceintelligence.com/EMT-Deals-Table/

Its sorting like this:
$1,000,000
$100,000,000
$2,000,000

Instead of this:
$1,000,000
$2,000,000
$100,000,000