Acquisitions and Divestitures - Consideration Transferred (Details) - USD ($) $ in Thousands			9 Months Ended
	Jan. 19, 2017	Mar. 01, 2016	Sep. 30, 2017	Sep. 30, 2016
Intralinks Holdings, Inc.
Business Acquisition [Line Items]
Cash consideration for outstanding Intralinks' common shares	$ 746,071
Issuance of Common Stock			$ (4,700)	$ 0
Cash consideration for accelerated equity awards to Intralinks' employees upon change in control	7,873
Cash consideration for vested unexercised Intralinks' stock options	19,838
Cash consideration for existing Intralinks' debt	77,800
Cash consideration for shareholders purchase price settlement	2,794
Total cash consideration transferred	854,376
Fair value of replacement awards	4,702
Total consideration transferred	$ 859,078
Openwave Messaging
Business Acquisition [Line Items]
Cash consideration for outstanding Intralinks' common shares		$ 102,538
Issuance of Common Stock		(22,000)	$ 0	$ (22,000)
Intellectual Property Settlement		(10,000)
Total cash consideration transferred		92,538
Total consideration transferred		$ 114,538