ing - Yep gerund forms are a killer. Sellable domains are those that keep it at the basic form of the verb. However, "idscreening" is a bit of a different case. It has a nounish quality to it -- is that making sense?
Anyways at first I thought the domain would lack in purpose but a Google search yielded some ideas.
http://www.google.com/search?hl=en&i...d+screening%22
"Id screening" describes a security related product. That should make it sellable....however in another note "id screening" would not be a good fit for a site selling such a service. It would be more natural to operate under the brand site.
Im leaning towards giving this domain a lacking significant value appraisal. But I'll hold back. Its a tough one because it meets the criteria for being a good domain (it describes a product) but its main problem is the term itself is just so mundane that the value suffers because end-users would just prefer to sell under the company name instead.
.us - I make this comment for every non-tier 1 term that ends with a .us extension. The market isn't strong enough now to support the domains you are holding.