Acquisitions, Contingent Consideration by Acquisition (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Other current liabilities [Member]
Business Acquisition, Contingent Consideration [Line Items]
Contingent Consideration, Liability	$ 2,647	$ 2,842
Other non current liabilities [Member]
Business Acquisition, Contingent Consideration [Line Items]
Contingent Consideration, Liability	1,085	1,948
Hyperspring, LLC [Member] | Other current liabilities [Member]
Business Acquisition, Contingent Consideration [Line Items]
Contingent Consideration, Liability	2,647	2,152
Hyperspring, LLC [Member] | Other non current liabilities [Member]
Business Acquisition, Contingent Consideration [Line Items]
Contingent Consideration, Liability	1,085	1,948
IntelliQlik, LLC [Member] | Other current liabilities [Member]
Business Acquisition, Contingent Consideration [Line Items]
Contingent Consideration, Liability	0	213
EnVision Systems, Inc. [Member] | Other current liabilities [Member]
Business Acquisition, Contingent Consideration [Line Items]
Contingent Consideration, Liability	$ 0	$ 477