Home Page is a "Post" Not a "Page" so I Can't Remove the Sidebar

I’m using Twenty Twelve. My website is: http://www.sdocr.com. I want to remove the right sidebar on all of my pages, and have been able to do so by selecting “Full-width page template – no sidebar” under “Template” in “Page Attributes,” but my homepage is considered a “Post” and does not have the same option, so I can’t remove the right sidebar there. How can I resolve this?