Does throughput includes CPU idle time also?
You are correct!

According to the defenition Throughput (in case of scheduling in OS) is :


  Number of processes that can be completed in a unit of time.


The process can use both the CPU or the I/O operations. So the I/O time and idle times and CPU time are calculated in throughput.

Note: CPU idle time is not calculated when you want to have the Utilization of the CPU. So in your case CPU Utilization is 42/47.