Revenue - Summary of Disaggregates Major Categories of Revenues (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Revenues
Total revenues	$ 128,800	$ 98,227	$ 282,716	$ 217,735
Recurring [Member]
Revenues
Total revenues	126,609	96,351	278,494	214,265
Implementation and Other [Member]
Revenues
Total revenues	$ 2,191	1,876	$ 4,222	3,470
As Adjusted [Member]
Revenues
Total revenues		98,227		217,735
As Adjusted [Member] | Recurring [Member]
Revenues
Total revenues		96,351		214,265
As Adjusted [Member] | Implementation and Other [Member]
Revenues
Total revenues		$ 1,876		$ 3,470