Acquisitions and Divestitures - Schedule of Assets and Liabilities Acquired (Details) - USD ($) $ in Thousands	Jan. 03, 2017	Jun. 30, 2017	Dec. 31, 2016
Business Acquisition [Line Items]
Goodwill		$ 1,617,105	$ 1,585,893
Unidesk Corporation [Member]
Business Acquisition [Line Items]
Current assets	$ 5,321
Property and equipment	131
Intangible assets	39,470
Goodwill	31,212
Other assets	90
Assets acquired	76,224
Other current liabilities assumed	2,290
Current portion of deferred revenues	3,042
Long term portion of deferred revenues	2,412
Long-term liabilities assumed	4,086
Deferred taxes	1,247
Net assets acquired	$ 63,147
Weighted average useful life	4 years