I hadn't actually looked, so I logged into my XFinity account and followed the links to see my phone activity. Right there, I have the opportunity to select:
C. Incoming calls I missed
D. Incoming calls I answered
E. Outgoing calls I placed
There's a full history of name, number, duration and date/time of all calls. Since I have my own answering system, there aren't any voicemails or trash, but the last three are filled with full information.
A little history on my first two phone numbers. I originally signed up both numbers with Comcast as part of a triple play package. What I didn't know (wasn't told at the time) is that Forward-on-Busy (call hunting) is not available for residential customers. It's only available for business customers. And, for business customers, both lines in the hunt group must be Comcast business numbers. Of course, if I did that, then I wouldn't be eligible for the triple-play package on the residential side (even though it's the same company). Argh!
What I ended up doing was pulling my primary number from Comcast (leaving the 2nd line to enable the triple-play), and moving it to ViaTalk VoIP. ViaTalk has all the features available, including the various flavors of Call Forwarding.
Edit: Full call logs (in and out) are also logged on my ViaTalk line. They also have multiple ways to block or reroute incoming calls.