Talk:1600 Pennsylvania Avenue

Is this actually an idiom? It seems to be a straightforward case of metonymy. Certainly "white house" is not an idiom, even when being used to describe the executive branch or a decision made by the president. What is idiomatic about this address?2602:306:3461:ECC0:8893:76BB:3EAF:4BEB 18:11, 29 January 2015 (UTC)