Quarterly Results of Operations (Details) (USD $)	3 Months Ended																12 Months Ended
	Dec. 31, 2012		Sep. 30, 2012		Jun. 30, 2012		Mar. 31, 2012		Dec. 31, 2011		Sep. 30, 2011		Jun. 30, 2011		Mar. 31, 2011		Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Selected Quarterly Financial Information [Abstract]
Revenue, Net	$ 30,780,000	[1]	$ 26,025,000	[2]	$ 26,824,000	[3]	$ 27,531,000		$ 29,689,000		$ 26,595,000	[4]	$ 27,860,000		$ 29,177,000	[5]	$ 111,129,000	$ 113,321,000	$ 103,988,000
Gross Profit	19,130,000	[1]	15,222,000	[2]	15,875,000	[3]	17,244,000		18,938,000		16,312,000	[4]	18,092,000		19,787,000	[5]	67,440,000	73,129,000	72,258,000
Gain on settlement and change in fair value of contingent consideration									0	[6]	0	[4],[6]	(6,439,000)	[6]	506,000	[5],[6]	0	(5,933,000)	(1,946,000)
Net (loss) income	(973,000)	[1]	(608,000)	[2]	(399,000)	[3]	(1,438,000)		(6,527,000)		686,000	[4]	3,393,000		(1,125,000)	[5]	(3,419,000)	(3,573,000)	3,803,000
Net (loss) income per common share - basic (in dollars per share)	$ (0.04)	[1],[7]	$ (0.02)	[2],[7]	$ (0.02)	[3],[7]	$ (0.06)	[7]	$ (0.27)	[7]	$ 0.03	[4],[7]	$ 0.14	[7]	$ (0.08)	[5],[7]	$ (0.14)	$ (0.17)	$ 0.01
Net (loss) income per common share - diluted (in dollars per share)	$ (0.04)	[1],[7]	$ (0.02)	[2],[7]	$ (0.02)	[3],[7]	$ (0.06)	[7]	$ (0.27)	[7]	$ 0.03	[4],[7]	$ 0.13	[7]	$ (0.08)	[5],[7]	$ (0.14)	$ (0.17)	$ 0.01
Immaterial Corrections [Member]
Effect of Fourth Quarter Results [Abstract]
Effect of Fourth Quarter Events, Increase Operating Expenses Amount					51,000
Effect of Fourth Quarter Events, Decrease Allocated Share Based Compensation Expense Amount	106,000		32,000
Effect of Fourth Quarter Events, Decrease in Revenue, Amount	(87,000)														88,000
Effect of Fourth Quarter Events, Increase Royalty Expense Amount	39,000										20,000
Effect of Fourth Quarter Events, Increase Sales Tax Expense, Amount	106,000
Effect of Fourth Quarter Events, Increase Consulting Expense, Amount															36,000
Effect of Fourth Quarter Events, Incresae in Royalty and Consulting Expense, Amount											127,000
MedCafe, Inc. [Member]
Effect of Fourth Quarter Results [Abstract]
Contingent consideration recorded in connection with business acquisitions													$ 6,400,000

[1] During the fourth quarter of 2012, the Company recorded correcting entries to reduce revenue by $87 thousand for the correction of immaterial errors in deferred revenue balances, to reduce stock-based compensation expense by $106 thousand for the correction of immaterial errors in additional paid-in capital, to increase royalty expenses by $39 thousand for the correction of immaterial errors in accrued royalties and to increase sales tax expense by $106 thousand for the correction of immaterial errors in other assets.

[2] During the third quarter of 2012, the Company recorded a correcting entry to reduce stock-based compensation expense by $32 thousand for the correction of immaterial errors in additional paid-in capital for the three months ended September 30, 2012.

[3] During the second quarter of 2012, the Company recorded correcting entries to increase operating expenses by $51 thousand for the correction of immaterial errors in accrued expenses in the three months ended June 30, 2012.

[4] During the third quarter of 2011, the Company recorded correcting entries to increase royalty and consulting expenses by $127 thousand for the correction of immaterial errors in capitalization of costs related to internal use software.

[5] During the first quarter of 2011, the Company recorded correcting entries to increase consulting expenses by $36 thousand for the correction of immaterial errors in accrued expenses and to increase revenue by $88 thousand for the correction of immaterial errors in deferred revenue.

[6] For the three months ended June 30, 2011, includes a $6.4 million gain relating to the settlement of the contingent consideration liability with the sellers of MedCafe, Inc., a company that Epocrates acquired in 2010.

[7] Net (loss) income per share for the four quarters of each fiscal year may not sum to the total for the fiscal year because of the different number of shares outstanding during each period.