SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Advertising cost
Advertising	$ 55,282	$ 48,909	$ 46,081
Cash and Cash Equivalents
Maximum original maturity period of cash equivalents	3 months
Cash held at various banking institutions	118,216	65,082	46,275	20,913
Cash held in non-interest-bearing accounts	67,200
Cash held in foreign bank accounts	$ 51,012	$ 40,933