The absent-minded teller

An absent-minded bank teller switched the dollars and cents when he cashed a cheque for Mr. Brown, giving him dollars instead of cents, and cents instead of dollars. After buying a five-cent newspaper, Brown discovered that he had left with exactly twice as much as his original cheque. What was the amount of the cheque? 

Source: MY BEST MATHEMATICAL AND LOGIC PUZZLES by Martin Gardner.

Solution