Stock-Based Compensation (Summary of Stock-Based Compensation Expense) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Employee Service Stock-based Compensation, Allocation of Recognized Period Costs [Line Items]
Allocated stock-based compensation expense	$ 6,311	$ 4,330	$ 11,413	$ 8,044
Cost of subscriptions [Member]
Employee Service Stock-based Compensation, Allocation of Recognized Period Costs [Line Items]
Allocated stock-based compensation expense	325	175	468	364
Cost of maintenance [Member]
Employee Service Stock-based Compensation, Allocation of Recognized Period Costs [Line Items]
Allocated stock-based compensation expense	85	196	246	341
Cost of services [Member]
Employee Service Stock-based Compensation, Allocation of Recognized Period Costs [Line Items]
Allocated stock-based compensation expense	639	582	1,236	1,124
Total included in cost of revenue [Member]
Employee Service Stock-based Compensation, Allocation of Recognized Period Costs [Line Items]
Allocated stock-based compensation expense	1,049	953	1,950	1,829
Sales and marketing [Member]
Employee Service Stock-based Compensation, Allocation of Recognized Period Costs [Line Items]
Allocated stock-based compensation expense	804	588	1,506	1,059
Research and development [Member]
Employee Service Stock-based Compensation, Allocation of Recognized Period Costs [Line Items]
Allocated stock-based compensation expense	1,186	762	2,164	1,424
General and administrative [Member]
Employee Service Stock-based Compensation, Allocation of Recognized Period Costs [Line Items]
Allocated stock-based compensation expense	3,272	2,027	5,793	3,732
Total included in operating expenses [Member]
Employee Service Stock-based Compensation, Allocation of Recognized Period Costs [Line Items]
Allocated stock-based compensation expense	$ 5,262	$ 3,377	$ 9,463	$ 6,215