PROPERTY AND EQUIPMENT - NET (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	$ 100,275	$ 89,666
Less accumulated depreciation and amortization	(39,776)	(34,532)
Total	60,499	55,134
Depreciation and amortization expenses	$ 11,979	12,134	$ 12,335
Computer hardware
Property, Plant and Equipment [Line Items]
Useful Life (in years)	3 years
Property, Plant and Equipment, Gross	$ 36,612	32,374
Leasehold improvements
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	$ 6,801	6,287
Furniture and fixtures
Property, Plant and Equipment [Line Items]
Useful Life (in years)	7 years
Property, Plant and Equipment, Gross	$ 8,990	7,348
Purchased computer software
Property, Plant and Equipment [Line Items]
Useful Life (in years)	3 years
Property, Plant and Equipment, Gross	$ 4,099	3,606
Office equipment
Property, Plant and Equipment [Line Items]
Useful Life (in years)	7 years
Property, Plant and Equipment, Gross	$ 8,307	5,043
Building
Property, Plant and Equipment [Line Items]
Useful Life (in years)	50 years
Property, Plant and Equipment, Gross	$ 34,002	17,123
Land improvements
Property, Plant and Equipment [Line Items]
Useful Life (in years)	20 years
Property, Plant and Equipment, Gross	$ 1,464	0
Construction in Progress
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	$ 0	$ 17,885