Description of Business and Summary of Significant Accounting Policies (Goodwill) (Details) - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2015	Dec. 31, 2014
Business Combination Segment Allocation [Line Items]
Document Period End Date	Sep. 30, 2015
Goodwill [Roll Forward]
Beginning Balance	$ 402,220	$ 337,068
Additions, net	10,382	68,503
Foreign currency translation adjustments	(4,509)	(3,351)
Ending Balance	$ 408,093	$ 402,220