Several VoIP Detective reports, including the inbound call report, and the admin report will show the user which answered a call to a shared line or hunt group.  This is labeled as "Associated User" This is done by associating a CUCM end user with a device in CUCM.  After that is done, the CDRs provided to VoIP Detective will include this information.

For example, here is an inbound call report for the sales hunt group

In order to see the associated user in the far right column, we'll need to associate each user to their device.  This is done by going to 

Cisco Unified CM Administration -> Device -> Phone

Then on the device page, change the "Owner User ID" to the proper CUCM end user.

From this point forward, calls answered by this user should associate their userid.