Goodwill and Intangible Assets - Finite-lived Intangibles (Details) (USD $)			12 Months Ended						1 Months Ended											1 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2013 Cost of revenues	Dec. 31, 2012 Cost of revenues	Dec. 31, 2011 Cost of revenues	Dec. 31, 2013 Finite-lived intangible assets	Dec. 31, 2012 Finite-lived intangible assets	Dec. 31, 2011 Finite-lived intangible assets	Apr. 30, 2012 Sonar Limited	Dec. 31, 2013 Developed technology	Dec. 31, 2012 Developed technology	Dec. 31, 2013 Customer relationships	Dec. 31, 2012 Customer relationships	Dec. 31, 2013 Domains/trademarks/tradenames	Dec. 31, 2012 Domains/trademarks/tradenames	Dec. 31, 2013 Software license rights	Dec. 31, 2012 Software license rights	Dec. 31, 2013 Non-compete agreements	Dec. 31, 2012 Non-compete agreements	Jan. 31, 2012 Intellectual property rights
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 8,784,000	$ 8,784,000								$ 3,800,000	$ 3,800,000	$ 2,400,000	$ 2,400,000	$ 320,000	$ 320,000	$ 1,654,000	$ 1,654,000	$ 610,000	$ 610,000
Accumulated Amortization	(4,152,000)	(1,897,000)								(1,649,000)	(700,000)	(1,042,000)	(441,000)	(278,000)	(118,000)	(759,000)	(459,000)	(424,000)	(179,000)
Net Carrying Amount	4,632,000	6,887,000								2,151,000	3,100,000	1,358,000	1,959,000	42,000	202,000	895,000	1,195,000	186,000	431,000
Intangible assets acquired																				800,000
Additional finite lived intangible assets									7,100,000
Amortization expense			$ 1,300,000	$ 1,000,000	$ 100,000	$ 2,300,000	$ 1,700,000	$ 100,000