Acquisition (Details) (ThinkNear, USD $)	0 Months Ended		0 Months Ended
	Oct. 10, 2012	Sep. 30, 2013 Prepaid and other assets	Oct. 10, 2012 Developed technology	Oct. 10, 2012 Restricted common stock	Oct. 10, 2012 Options to purchase common stock
Business Acquisition [Line Items]
Percentage of voting interests acquired	100.00%
Consideration transferred	$ 22,500,000
Cash consideration transferred	18,400,000
Equity interests issued and options assumed (in shares)				586,580	74,491
Equity interests issued and options assumed	4,100,000			3,600,000	457,000
Amortization period for the fair value of equity interests issued				1 year 9 months 11 days	2 years 9 months 26 days
Equity interests issued, fair value per share (in dollars per share)				$ 6.23	$ 6.13
Business Combination, Recognized Identifiable Assets Acquired, Goodwill, and Liabilities Assumed, Net [Abstract]
Cash	181,000
Accounts receivable	410,000
Other assets	259,000
Developed technology	5,100,000
Goodwill	14,343,000
Liabilities assumed	(1,858,000)
Total value of assets acquired and liabilities assumed	18,435,000
Fair value of intangible assets			5,100,000
Useful life of intangible assets			3 years
Cash deposited in escrow	$ 2,700,000	$ 2,700,000