He was good in that role. Just for the record, so was Jane.
Rather than a TV series, thought it was a movie? Only one seen but now find there were several made...a ‘franchise’
Originally a “made for TV” movie, it was a surprise hit that stimulated several direct sequels. It also spun off a TV series “The Librarians”, but without Newhart. I’ve only seen a few of the series, which involves a group of “apprentice” librarians-in-training, in which Noah Wylie makes the occasional appearance. Newhart may had done a cameo or two, but not in the ones I watched.