Detailed, Step-by-Step Teacher Answer Keys

The teacher answer keys give only the answers (often without units). I have been teaching for a long time but I am new to a particular prep (physics). As a first time teacher in a new subject area, it would be helpful to have more detailed keys to show how to arrive at the solution. It would save me time having to work them all out myself and I could use the key to help structure a discussion or explanation of the problem.