SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Details 2) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013
Accounting Policies [Abstract]
Maturity period from date of purchase, short-term investments classified as cash equivalents, less than (in days)	91 days
Property and equipment
Net book value	$ 302,459	$ 293,964
Buildings and leasehold improvements | Minimum
Property and equipment
Estimated useful lives, minimum (in years)	3 years
Buildings and leasehold improvements | Maximum
Property and equipment
Estimated useful lives, minimum (in years)	39 years
Computer equipment and capitalized software | Minimum
Property and equipment
Estimated useful lives, minimum (in years)	2 years
Computer equipment and capitalized software | Maximum
Property and equipment
Estimated useful lives, minimum (in years)	3 years
Furniture and other equipment | Minimum
Property and equipment
Estimated useful lives, minimum (in years)	3 years
Furniture and other equipment | Maximum
Property and equipment
Estimated useful lives, minimum (in years)	12 years
Software and Software Development Costs
Property and equipment
Net book value	$ 36,900	$ 30,900