  We present far-infrared and submillimeter maps from the Herschel Space
Observatory and the James Clerk Maxwell Telescope of the debris disk host star
AU Microscopii. Disk emission is detected at 70, 160, 250, 350, 450, 500 and
850 micron. The disk is resolved at 70, 160 and 450 micron. In addition to the
planetesimal belt, we detect thermal emission from AU Mic's halo for the first
time. In contrast to the scattered light images, no asymmetries are evident in
the disk. The fractional luminosity of the disk is $3.9 \times 10^{-4}$ and its
mm-grain dust mass is 0.01 MEarth (+/- 20%). We create a simple spatial model
that reconciles the disk SED as a blackbody of 53 +/- 2 K (a composite of 39
and 50 K components) and the presence of small (non-blackbody) grains which
populate the extended halo. The best fit model is consistent with the "birth
ring" model explored in earlier works, i.e., an edge-on dust belt extending
from 8.8-40 AU, but with an additional halo component with an $r^{-1.5}$
surface density profile extending to the limits of sensitivity (140 AU). We
confirm that AU Mic does not exert enough radiation force to blow out grains.
For stellar mass loss rates of 10-100x solar, compact (zero porosity) grains
can only be removed if they are very small, consistently with previous work, if
the porosity is 0.9, then grains approaching 0.1 micron can be removed via
corpuscular forces (i.e., the stellar wind).
