Revenue (Details) - USD ($)	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Dec. 31, 2018
Disaggregation of Revenue [Line Items]
Total net revenues	$ 719,143,000	$ 697,192,000
Short-term contract liabilities	1,303,210,000		$ 1,345,243,000
Long-term portion of deferred revenues	453,507,000		$ 489,329,000
Deferred revenue recognized	455,700,000	454,800,000
Impairment charges related to contract assets	0	0
Impairment of capitalized costs	0	0
Transferred at Point in Time [Member]
Disaggregation of Revenue [Line Items]
Total net revenues	162,964,000	182,326,000
Transferred over Time [Member]
Disaggregation of Revenue [Line Items]
Total net revenues	$ 556,179,000	514,866,000
Minimum [Member]
Disaggregation of Revenue [Line Items]
Intangible asset life	3 years
Maximum [Member]
Disaggregation of Revenue [Line Items]
Intangible asset life	7 years
Customer Relationships [Member] | Minimum [Member]
Disaggregation of Revenue [Line Items]
Intangible asset life	3 years
Customer Relationships [Member] | Maximum [Member]
Disaggregation of Revenue [Line Items]
Intangible asset life	5 years
Sales, Marketing and Services Expense [Member]
Disaggregation of Revenue [Line Items]
Amortization of capitalized contract acquisition costs	$ 10,700,000	$ 7,900,000