Revenues by Service Offering (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011
Revenue from External Customer [Line Items]
Revenues	$ 110,078	$ 86,423	$ 308,261	$ 239,401
Software development
Revenue from External Customer [Line Items]
Revenues	73,894	56,580	206,045	157,025
Application testing services
Revenue from External Customer [Line Items]
Revenues	22,001	17,859	61,297	48,523
Application maintenance and support
Revenue from External Customer [Line Items]
Revenues	8,806	7,101	25,775	20,502
Infrastructure services
Revenue from External Customer [Line Items]
Revenues	3,213	2,299	8,965	6,353
Licensing
Revenue from External Customer [Line Items]
Revenues	771	1,078	1,993	2,686
Reimbursable expenses and other revenues
Revenue from External Customer [Line Items]
Revenues	$ 1,393	$ 1,506	$ 4,186	$ 4,312