OPERATING SEGMENTS, Revenues by Service Offering (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Revenue from External Customer [Line Items]
Revenues	$ 217,781	$ 174,695	$ 417,826	$ 335,079
Software development
Revenue from External Customer [Line Items]
Revenues	151,743	119,852	291,778	230,539
Application testing services
Revenue from External Customer [Line Items]
Revenues	42,310	34,196	79,340	65,966
Application maintenance and support
Revenue from External Customer [Line Items]
Revenues	17,970	14,513	35,102	25,891
Infrastructure services
Revenue from External Customer [Line Items]
Revenues	2,747	3,484	5,920	7,238
Licensing
Revenue from External Customer [Line Items]
Revenues	769	978	1,587	1,806
Reimbursable expenses and other revenues
Revenue from External Customer [Line Items]
Revenues	$ 2,242	$ 1,672	$ 4,099	$ 3,639