Is multi-thread output from System.out.println interleaved

If multiple threads call System.out.println(String) without synchronization, can the output get interleaved? Or is the write of each line atomic? The API makes no mention of synchronization, so this seems possible, or is interleaved output prevented by buffering and/or the VM memory model, etc.?

EDIT:

For example, if each thread contains:

System.out.println("ABC");

is the output guaranteed to be:

ABC
ABC

or could it be:

AABC
BC