Yes, you won.
-140 is basically the ratio of the payout you get. If you bet $140, you would win $100. Conversely, if you bet an underdog, for example +180 then if you bet $100, you would win $180.
There is only one other way to bet a baseball game (sides) and that is a run-line. The run-line will either be +1 1/2 or -1 1/2 and that means the team you bet on would have to win/lose by 2. There is also a +/- ratio associated with run-lines.
Hope that helps.