If not, the publishing feature for the site is turned on. Hopefully you should never have to delete this library, you can just rename it and use it as the main document respostory for the site, BUT if for some reason you have managed to royally ruin it and there is no other way :
Turn off publishing in the site
Delete the Documents library
Turn publishing back on (the library should be recreated)
Please make sure you are aware of any consequences. Check out another of my posts here which touches of this subject also.