Revenues - Additional Information (Details) - USD ($) $ in Thousands		3 Months Ended
	Jan. 01, 2018	Mar. 31, 2018	Dec. 31, 2017
Deferred Revenue Arrangement [Line Items]
Retained earnings		$ 851,495	$ 766,856
Maintenance contract term		1 year
Deferred revenue presented net within contract assets arised from contract		$ 29,300
Deferred revenue recognized		76,500
Revenue expected to be recognized from remaining performance obligations		266,300
Revenue expected to be recognized from remaining performance obligations in next twelve months		$ 174,100
Software-enabled Services [Member]
Deferred Revenue Arrangement [Line Items]
Notice period for cancelling contract		90 days
Minimum [Member] | Software-enabled Services [Member]
Deferred Revenue Arrangement [Line Items]
Revenue recognition period		1 year
Maximum [Member] | Software-enabled Services [Member]
Deferred Revenue Arrangement [Line Items]
Revenue recognition period		5 years
Effect of Change [Member] | ASU 2014-09 [Member]
Deferred Revenue Arrangement [Line Items]
Retained earnings	$ 65,800
Cumulative impact on retained earnings, net of tax	$ 47,900
Decrease in revenue		$ (11,800)