What is "dollars to donuts"

Usage examples of "dollars to donuts".

And I'll bet dollars to donuts that Dee manages to get Alex to take her out to dinner tonight.

They were Homicide, they were bent, and he'd bet dollars to donuts they weren't even investigating the case.

They were Homicide, they were bent, and he’d bet dollars to donuts they weren’t even investigating the case.

And dollars to donuts she'll never go to see anyone, because they can't take a chance of Amanda talking to anyone.