Detaches a virtual private gateway from a VPC. You do this if you're planning to turn off the VPC and not use it anymore. You can confirm a virtual private gateway has been completely detached from a VPC by describing the virtual private gateway (any attachments to the virtual private gateway are also described).
You must wait for the attachment's state to switch to detached
before you can delete the VPC or attach a different VPC to the virtual private gateway.