Acquisitions (Details) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2013	Dec. 31, 2012	Apr. 17, 2013 Pulse
Purchase price allocation included in Company condensed consolidated balance sheets
Net tangible assets			$ 221
Goodwill	150,831	115,214	35,617	[1]
Intangible assets			14,000	[2]
Deferred tax liability			(2,227)
Total purchase price consideration			$ 47,611	[3]

[1] The goodwill represents the excess value over both tangible and intangible assets acquired. The goodwill in this transaction is primarily attributable to expected operational synergies, the assembled workforce, and the future development initiatives of the assembled workforce. None of the goodwill is expected to be deductible for tax purposes.

[2] Identifiable definite-lived intangible assets were comprised of developed technology of $9.5 million, trade name of $2.7 million, registered user base of $1.2 million and backlog of $0.6 million. The overall weighted-average life of the identifiable definite-lived intangible assets acquired was 2.9 years, which will be amortized on a straight-line basis over their estimated useful lives.

[3] Subject to adjustment based on (i) purchase price adjustment provisions and (ii) indemnification obligations of the acquired company stockholders.