Condensed Consolidated Statements of Comprehensive Loss (Unaudited) (USD $)
In Thousands, unless otherwise specified
3 Months Ended 6 Months Ended
Jun. 30, 2012
Jun. 30, 2011
Jun. 30, 2012
Jun. 30, 2011
Condensed Consolidated Statements of Comprehensive Loss [Abstract]        
Net loss $ (1,665) $ (3,025) $ (5,039) $ (6,362)
Other comprehensive loss (net of tax):        
Change in unrealized gain (loss) on investments (19) 1 35 2
Change in unrealized gain (loss) on derivatives (585) (218) 71 (471)
Comprehensive loss (2,269) (3,242) (4,933) (6,831)
Comprehensive loss attributable to noncontrolling interests 132 149 235 280
Comprehensive loss attributable to Imperva, Inc. stockholders $ (2,137) $ (3,093) $ (4,698) $ (6,551)