ESPN has a stat for you! Real Plus-Minus (RPM): Plus-Minus that accounts for quality of teammates and other factors! Has WAR, too. Though, not sure how good it is yet.
Hibbert's Offensive and defensive RPM (ORPM and DRPM):
ORPM: -1.20
DRPM: 3.59
RPM: 2.39
WAR: 6.56