Kim Kardashian and Kanye West are way further along in their divorce proceedings than we thought, because their most valuable asset is already signed, sealed and delivered to Kim at a price of $20 million.

According to legal docs -- obtained by TMZ -- Kim is now the sole owner of the Hidden Hills estate ... Kanye signed over his rights to the property and the transfer was recorded with the County of L.A. on Sept. 28.

This is really significant, because there have been rumblings Kim and Kanye have been trying to salvage their marriage. If that were the case, it's doubtful huge assets like the family home would be formally transferred. What would normally happen is that they'd make an agreement to transfer various properties, but they wouldn't pull the trigger until they knew the divorce would go through.

This is a screaming signal there will be no reconciliation. The divorce is full steam ahead. In return for becoming sole owner of the Hidden Hills estate, Kim paid Kanye $20 million -- that's the so-called "buy out." Fact is ... Kim did well for herself, because that's the price they paid in 2014, before Kanye literally razed the house to the ground and rebuilt it, and it's now worth around $60 mil.

The home is a masterpiece, Kanye worked with architects and designers from around the world to finish it ... complete with a basketball court, detached gym, massive swimming pool ... and 2 kitchens!

Kim and the kids have remained in the home since February when she filed for divorce, and our sources say the home is the most important part of the property settlement for Kim.

So, the question ... what was the deal with Kim and Kanye hanging out, Kim attending the various "Donda" listening party events, Kanye showing up for 'SNL,' and on and on? Well, whether they tried to work it out, it seems that's in the rearview because the divorce is barreling down the tracks.