  Blazars are known to show periods of quiescence followed by outbursts visible
throughout the electromagnetic spectrum. We present a novel maximum likelihood
approach to capture this bimodal behavior by examining blazar radio variability
in the flux-density domain. We separate quiescent and flaring components of a
source's light curve by modeling its flux-density distribution as a series of
"off" and "on" states. Our modeling allows us to extract information regarding
the flaring ratio, duty cycle, and the modulation index in the "off"-state, in
the "on"-state, as well as throughout the monitoring period of each blazar. We
apply our method to a flux-density-limited subsample from the Owens Valley
Radio observatory's 15 GHz blazar monitoring program, and explore differences
in the variability characteristics between BL Lacs and FSRQs as well as between
$\gamma$-ray detected and non-detected sources. We find that: (1) BL Lacs are
more variable and have relatively larger outbursts than the FSRQs, (2)
unclassified blazar candidates in our sample show similar variability
characteristics as the FSRQs, and (3) $\gamma$-ray detected differ from the
$\gamma$-ray non-detected sources in all their variability properties,
suggesting a link between the production of $\gamma$-rays and the mechanism
responsible for the radio variability. Finally, we fit distributions for blazar
flaring ratios, duty cycles, and on- and off- modulation indices that can be
used in population studies of variability-dependent blazar properties.
