Deductions & credits

Thank you everyone.

I have about $20,000 in my traditional IRA as uninvested cash (don't ask me why haha). 

Anyway, I would like to just convert that $20K to the Roth IRA.

As I said before, all the money in my traditional IRA is from after-tax money and I never got any tax deduction from this. 
Do I need to withhold tax for that $20K that I wish to convert?