INVESTMENTS (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013		Dec. 31, 2012
Schedule of Trading Securities and Other Trading Assets [Line Items]
Trading, Amortized cost			$ 18,580
Trading, Gross unrealized gains			0
Trading, Gross unrealized losses			0
Trading, Estimated fair value			18,580
Schedule of Available-for-sale Securities [Line Items]
Amortized cost	47,851
Gross unrealized gains	12
Gross unrealized losses	(28)
Estimated fair value	47,835
U.S. Treasury securities and debt securities of U.S. Government agencies
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale, maximum maturity period	2 years
Available-for-Sale, Amortized cost	3,001	[1]
Available-for-Sale, Gross unrealized gains	0	[1]
Available-for-Sale, Gross unrealized losses	(3)	[1]
Available-for-Sale, Estimated fair value	2,998	[1]
Corporate debt securities
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale, maximum maturity period	2 years
Available-for-Sale, Amortized cost	31,319	[1]
Available-for-Sale, Gross unrealized gains	0	[1]
Available-for-Sale, Gross unrealized losses	(22)	[1]
Available-for-Sale, Estimated fair value	31,297	[1]
Commercial paper
Schedule of Trading Securities and Other Trading Assets [Line Items]
Trading, maximum maturity period			1 year
Trading, Amortized cost			5,026	[2]
Trading, Gross unrealized gains			0	[2]
Trading, Gross unrealized losses			0	[2]
Trading, Estimated fair value			5,026	[2]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale, maximum maturity period	1 year
Available-for-Sale, Amortized cost	8,485	[1]
Available-for-Sale, Gross unrealized gains	12	[1]
Available-for-Sale, Gross unrealized losses	0	[1]
Available-for-Sale, Estimated fair value	8,497	[1]
Term deposits
Schedule of Trading Securities and Other Trading Assets [Line Items]
Trading, maximum maturity period			1 year
Trading, Amortized cost			7,036	[2]
Trading, Gross unrealized gains			0	[2]
Trading, Gross unrealized losses			0	[2]
Trading, Estimated fair value			7,036	[2]
Guaranteed investment certificates
Schedule of Trading Securities and Other Trading Assets [Line Items]
Trading, maximum maturity period	1 year		1 year
Trading, Amortized cost	5,046	[2]	6,518	[2]
Trading, Gross unrealized gains	0	[2]	0	[2]
Trading, Gross unrealized losses	(3)	[2]	0	[2]
Trading, Estimated fair value	$ 5,043	[2]	$ 6,518	[2]

[1] Investments are designated as available-for-sale investments.

[2] Investments are designated as trading investments.