  We present a general class of entanglement criteria for continuous variable
systems. Our criteria are based on the Husimi $Q$-distribution and allow for
optimization over the set of all concave functions rendering them extremely
general and versatile. We show that several entropic criteria and second moment
criteria are obtained as special cases. Our criteria reveal entanglement of
families of states undetected by any commonly used criteria and provide clear
advantages under typical experimental constraints such as finite detector
resolution and measurement statistics.
