Details of Company's Contract Cost Assets (Detail) - USD ($) $ in Thousands		3 Months Ended	9 Months Ended
		Sep. 30, 2018	Sep. 30, 2018
Revenues [Line Items]
Closing balance	[1],[2]	$ 160,110	$ 160,110
Sales Incentive Programs
Revenues [Line Items]
Opening balance		24,808	23,227
Closing balance		26,459	26,459
Amortized contract cost asset amount		3,666	10,509
Process Transition Activities
Revenues [Line Items]
Opening balance		137,370	139,284
Closing balance		133,651	133,651
Amortized contract cost asset amount		$ 19,974	$ 54,874

[1] As a result of its adoption of ASC 606, the Company has reclassified deferred transition costs from “Prepaid expenses and other current assets” amounting to $49,248 and “Other assets” amounting to $84,403 to “Contract cost assets” amounting to $133,651.

[2] The cumulative impact of the adoption of ASC 606 resulted in a $160,110 increase in "Contract cost assets," which includes the reclassification of $133,651 (refer to note a in the table above) and a closing balance of $26,459 related to sales incentive programs, with a corresponding impact on retained earnings of $ 20,477 and on deferred tax assests of $5,982 which has been offset against deferred tax assets.