What is the frame attribution in xbrl's terminology?

To get all tesla's asset value at every financial report with sec's RESTful api:
https://data.sec.gov/api/xbrl/companyconcept/CIK0001318605/us-gaap/Assets.json

Open units--USD in the json,records in it,some record with frame attribution some without it,in this case the 80th record contains frame attribution,the 79th and 81th record contains no frame.What does frame mean in xbrl's terminology?

frame is not part of the XBRL standard; it's something that's added by by the SEC's API.

The meaning is described in the SEC's documentation. I believe that the absence of it on some facts is down to this bit:

The xbrl/frames API aggregates one fact for each reporting entity that is last filed that most closely fits the calendrical period requested

Where a fact does not have the frame property, it is no longer the most recently filed version of that fact. In the example above, you can see that fact 81 is the same as fact 80, but was filed three months earlier.