First thing that went through my mind, as well. I'd always hoped for a better idea of what went on at Ur than we have. The Bible is mostly silent except that Abram was commanded to leave, and We have the ancient traditions as briefly hinted at by Josephus from the First Century (even then it was at least two thousand years in the past.)
I'd begun to see the "Astrologers," the Chaldees of Ur 4,000 years ago much like the Mayans. Over the long course of history that happened there at the original Babylon, there had to have been a variety of periods both good and bad. We just don't have enough information. Though, we certainly have more than we had a century and a half ago.
Terah left Ur and headed to Canaan with his son Abram and his grandson Lot. But when he got to the land of Haran (also the name of his son (Lot's father) who had died in Ur), they stopped. Only after Terah died, did Abram finish the journey to Canaan.
So maybe the father was ordered by God, but he some reason to disobey and Abram was given the order afterward. I have always been fascinated by this story as people, particularly those with wealth and power, just didn't move from where they were from in those days.
Pikes to the backs of the head would certainly inspire some new ideas like "let's get the heck out of here!"
Actually, The Bible says that Abram was commanded to leave a place called Haran which is even today in Turkey. Abram's father Terah is the one that took his family and left Ur. The Bible says that the LORD says that He is the one who had brought Abram out Ur of the Chaldees, but the Bible says that the LORD commanded Abram to leave when he was living in Haran after his father had died.
It is interesting that the names Abraham's relatives and ancestors Peleg, Serug, Nahor and Terah, are names of cities around Haran and Haran was actually the name of Lot's father, Abrams brother.
Also, it is interesting to note that Abram came out of a family that actually had succumbed to idol worship according to Joshua 24:2.
Jos 24:2 And Joshua said unto all the people, Thus saith the LORD God of Israel, Your fathers dwelt on the other side of the flood in old time, [even] Terah, the father of Abraham, and the father of Nachor: and they served other gods.