It's ALL on jdparts.com

Look on page 34...

The idler, Key #5, uses 2 bearings, Key # 3, JD9214, available at your dealer for less than $8.00 each.

Inside Dimension 0.640 IN
Outside Dimension 1.575 IN
Width Outer Race 0.472 IN
Width Inner Race 0.720 IN

What MORE would you like the jdparts site to tell you???

Oh, yeah, the common industry # for the bearing (if you think you can beat the $8.00 price at DEERE) is 203KRR2.

The dimensions told me (from memory) that it was a version of a 203 bearing.

I fiddled a bit with the suffixes and entered the number into the "non John Deere part" in the search box, which confirmed the number I came up with crossed to the JD9214, so I knew I had "nailed it".

Had I been at the shop with my trusty SKF bearing reference at hand I wouldn't have had to guess since it would reference the DEERE #!