I do not belive it was a normal contrail my reasons for thinking this are:
1. It was moveing at, at least twice the speed of any airliner ive everseen
2. It was at a very high altiude
3. It was decending very fast
4. Because of the position of me the object and the sun i would have thought that i would have seen an aircraft silhouette as the oblect would have be back lit from the sun I have tried to explain this in the pic below

At that time of day (2030) the sun would be below the object relative to your line of sight, yes? Also depends on whether or not you were facing east or west (or whatever).
But anyway,I think it's most likely a contrail (lots of aircraft move faster than airliners), with space junk coming in a close second, despite the apparent lack of tumbling or "shedding", since you say it appeared to be descending.
