On Monday, we made several security improvements to Adobe Marketing Cloud's SSO service. In doing so, the auth redirects to ideas.omniture.com no longer work. This is an issue that occurs across all browsers, and is 100% not an issue on your end.
The last update I've received is that we are currently working with engineering and our Ideas Exchange platform host (Lithium) to get this resolved. This space will be updated as more information becomes available.