Condensed Consolidated Balance Sheets (USD $) In Thousands, unless otherwise specified	Sep. 30, 2012	Dec. 31, 2011
CURRENT ASSETS:
Cash and cash equivalents	$ 56,468	$ 96,025	[1]
Short-term investments	45,212	1,587	[1]
Restricted cash	591	687	[1]
Accounts receivable, net of allowance for doubtful accounts of $327 and $225 as of September 30, 2012 and December 31, 2011, respectively	26,719	25,736	[1]
Inventory	313	442	[1]
Deferred tax assets	250	246	[1]
Prepaid expenses and other current assets	2,624	1,352	[1]
Total current assets	132,177	126,075	[1]
Property and equipment, net	4,457	4,026	[1]
Severance pay fund	2,825	2,652	[1]
Restricted cash	666	666	[1]
Deferred tax assets	46	46	[1]
Other assets	608	77	[1]
TOTAL ASSETS	140,779	133,542	[1]
CURRENT LIABILITIES:
Accounts payable	3,730	3,534	[1]
Accrued compensation and benefits	10,107	7,491	[1]
Accrued and other current liabilities	3,848	4,408	[1]
Deferred revenue	26,430	21,982	[1]
Total current liabilities	44,115	37,415	[1]
Other liabilities	1,955	2,856	[1]
Deferred revenue	11,868	10,943	[1]
Accrued severance pay	3,238	2,760	[1]
TOTAL LIABILITIES	61,176	53,974	[1]
Commitments and Contingencies (Note 7)			[1]
STOCKHOLDERS' EQUITY:
Preferred stock, $0.0001 par value - 5,000,000 shares authorized, no shares issued and outstanding as of September 30, 2012 and December 31, 2011			[1]
Common stock, $0.0001 par value - 145,000,000 shares authorized, 24,037,971 and 22,978,166 shares issued and outstanding as of September 30, 2012 and December 31, 2011, respectively	2	2	[1]
Additional paid-in capital	153,328	147,085	[1]
Accumulated deficit	(72,793)	(66,130)	[1]
Accumulated other comprehensive income (loss)	32	(616)	[1]
TOTAL IMPERVA, INC. STOCKHOLDERS' EQUITY	80,569	80,341	[1]
Noncontrolling interest	(966)	(773)	[1]
TOTAL STOCKHOLDERS' EQUITY	79,603	79,568	[1]
TOTAL LIABILITIES AND STOCKHOLDERS' EQUITY	$ 140,779	$ 133,542	[1]

[1] The Condensed Consolidated Balance Sheet as of December 31, 2011 has been derived from the audited consolidated financial statements at that date but does not include all of the information and footnotes required by generally accepted accounting principles for complete financial statements.