Acquisitions (Narrative) (Details) - USD ($) $ in Thousands				1 Months Ended		3 Months Ended		12 Months Ended
	Jan. 08, 2016	May. 18, 2015	Jan. 08, 2015	Oct. 31, 2014	Jan. 31, 2014	Dec. 31, 2014	Jun. 30, 2014	Dec. 31, 2015
Sanbolic, Inc. [Member]
Business Acquisition [Line Items]
Total consideration in business acquisitions			$ 89,400
Cash acquired from the acquisition			200
Acquisition transaction costs			$ 500
Stock options converted and assumed (in shares)			37,057
Finite-lived Intangible assets acquired			$ 45,300
Grasshopper Group, LLC [Member]
Business Acquisition [Line Items]
Total consideration in business acquisitions		$ 161,500
Cash acquired from the acquisition		$ 3,600
Stock options converted and assumed (in shares)		105,765
Finite-lived Intangible assets acquired		$ 71,400
Other 2015 Acquisition [Member]
Business Acquisition [Line Items]
Finite-lived Intangible assets acquired								$ 980
Framehawk, Inc. [Member]
Business Acquisition [Line Items]
Total consideration in business acquisitions					$ 24,200
Cash acquired from the acquisition					$ 200
Acquisition transaction costs						$ 100
RightSignature, LLC [Member]
Business Acquisition [Line Items]
Total consideration in business acquisitions				$ 37,800
Cash acquired from the acquisition				$ 1,100
Acquisition transaction costs						200
Stock options converted and assumed (in shares)				67,500
Other 2014 Acquisition [Member]
Business Acquisition [Line Items]
Total consideration in business acquisitions						19,900	$ 17,200
Cash acquired from the acquisition						$ 200	$ 800
Stock options converted and assumed (in shares)						23,430
General and administrative | Sanbolic, Inc. [Member]
Business Acquisition [Line Items]
Acquisition related costs								300
General and administrative | Grasshopper Group, LLC [Member]
Business Acquisition [Line Items]
Acquisition related costs								$ 300
General and administrative | Other 2014 Acquisition [Member]
Business Acquisition [Line Items]
Acquisition transaction costs						$ 100
Subsequent Event [Member]
Business Acquisition [Line Items]
Finite-lived Intangible Assets Acquired	$ 23,600
Outsourced development and maintenance agreement, term of contract	3 years