Segment Information (Subscription Revenues) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Segment Reporting Information [Line Items]
Total Subscription revenue	$ 798,929	$ 748,697	$ 1,659,874	$ 1,467,840
Subscription [Member]
Segment Reporting Information [Line Items]
Total Subscription revenue	243,450	155,833	511,686	297,439
Subscription, SaaS [Member]
Segment Reporting Information [Line Items]
Total Subscription revenue	130,618	91,208	253,188	176,655
Subscription, Non-SaaS [Member]
Segment Reporting Information [Line Items]
Total Subscription revenue	$ 112,832	$ 64,625	$ 258,498	$ 120,784