OPERATING SEGMENTS, Revenues by Service Offering (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014
Revenue from External Customer [Line Items]
Revenues	$ 200,045	$ 160,384
Software development
Revenue from External Customer [Line Items]
Revenues	140,035	110,687
Application testing services
Revenue from External Customer [Line Items]
Revenues	37,030	31,770
Application maintenance and support
Revenue from External Customer [Line Items]
Revenues	17,132	11,378
Infrastructure services
Revenue from External Customer [Line Items]
Revenues	3,173	3,754
Licensing
Revenue from External Customer [Line Items]
Revenues	818	828
Reimbursable expenses and other revenues
Revenue from External Customer [Line Items]
Revenues	$ 1,857	$ 1,967