Revenue (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018		Dec. 31, 2017	[1],[2]
Disaggregation of Revenue [Line Items]
Net revenues	$ 809,823	$ 732,901	$ 748,697	$ 719,143	$ 801,870	$ 732,476	$ 742,365	$ 697,192	$ 3,010,564	$ 2,973,903	[1],[2]	$ 2,824,686
Short-term contract asset	12,200				4,600				12,200	4,600
Long-term contract asset	20,500				3,700				20,500	3,700
Current portion of deferred revenues	1,352,333				1,345,243				1,352,333	1,345,243
Long-term portion of deferred revenues	$ 443,458				$ 489,329				443,458	489,329
Deferred revenue recognized									1,330,000	1,250,000
Asset impairment charges related to contracts									0	0
Products and services transferred at a point in time
Disaggregation of Revenue [Line Items]
Net revenues									722,324	821,111
Products and services transferred over time
Disaggregation of Revenue [Line Items]
Net revenues									$ 2,288,240	$ 2,152,792

[1] As noted above, prior period amounts have not been adjusted under the modified retrospective method of adoption of the revenue recognition standard.

[2] Prior period amounts have not been adjusted under the modified retrospective method of adoption of the revenue recognition standard.