OPERATING SEGMENTS, Revenues by Service Offering (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Revenue from External Customer [Line Items]
Revenues	$ 140,150	$ 110,078	$ 397,532	$ 308,261
Software development [Member]
Revenue from External Customer [Line Items]
Revenues	93,870	73,894	267,948	206,045
Application testing services [Member]
Revenue from External Customer [Line Items]
Revenues	27,773	22,001	78,473	61,297
Application maintenance and support [Member]
Revenue from External Customer [Line Items]
Revenues	11,758	8,806	33,245	25,775
Infrastructure services [Member]
Revenue from External Customer [Line Items]
Revenues	3,754	3,213	10,625	8,965
Licensing [Member]
Revenue from External Customer [Line Items]
Revenues	809	771	2,107	1,993
Reimbursable expenses and other revenues [Member]
Revenue from External Customer [Line Items]
Revenues	$ 2,186	$ 1,393	$ 5,134	$ 4,186