Other Financial Information - Gain on Contract Settlement (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Gain on contract settlement	$ 0	$ 910	$ 534
Return of common stock in connection with contract settlement (shares)		388,888
TopoTarget
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Gain on contract settlement			500
Business acquisition, value of common stock issued			1,200
Contingent consideration, liability			$ 1,700