Working without notes 'cause I'm halfway to bed...
The Idols were a good series with some interesting quirks. The workhorse of the family was the WI-64; it had a few variants, which I've compared favorably to higher-end Epiphone SG & LP models.
I think the cheapest Idol was the bolt-neck WI-14, then the carved-edge WI-15, followed by the set-neck WI-18 (mahogany body & neck, & quilt top)
Like so many excellent Washburn models, though, the Blue Book valuation of Idols is about double what the guitars actually sell for. In near-mint condition, a WI-14 might be priced at $75-$125. On a recent search, it looked like the WI-64 were around $200.
Last year, my WI-66V cost me less than $250, delivered -- beautiful axe, but there was simply no demand.
So, basically, you didn't get a bargain
... but you did get a good guitar at a decent price. The worst I've heard said about the 18 is that the pickups could've been better selected for a mahogany/mahogany.