CASH, CASH EQUIVALENTS AND INVESTMENTS (Details) (USD $)
In Thousands, unless otherwise specified
 3 Months Ended 12 Months Ended 3 Months Ended 12 Months Ended 3 Months Ended 12 Months Ended 0 Months Ended
Mar. 31, 2014
Dec. 31, 2013
Mar. 31, 2014
Corporate Debt Securities [Member]
Dec. 31, 2013
Corporate Debt Securities [Member]
Mar. 31, 2014
US Treasury and Government [Member]
Dec. 31, 2013
US Treasury and Government [Member]
Mar. 31, 2014
Convertible notes [Member]
Dec. 31, 2013
Convertible notes [Member]
Mar. 31, 2014
Certificates of Deposit [Member]
Dec. 31, 2013
Certificates of Deposit [Member]
Jul. 17, 2012
Private Company [Member]
Convertible notes [Member]
Jul. 13, 2012
Plextronics, Inc. [Member]
Convertible notes [Member]
Cash and Cash Equivalents [Line Items]                        
Cash Equivalents, at Carrying Value                 $ 10,881 $ 11,358    
Cash equivalents, Unrealized Gains                 4 2    
Cash Equivalents, Gross Unrealized Losses                 (10) (16)    
Cash and Cash Equivalents, Fair Value Disclosure                 10,875 11,344    
Available-for-sale Debt Securities, Amortized Cost Basis 4,000   218,771 190,738 4,075 3,074 300 4,300     300  
Available-for-sale securities, Unrealized Gains     37 33 0 0 0 0        
Convertible promissory note stated interest rate                     5.00% 3.00%
Available-for-sale Securities     (17) (48) 0 0 0 0        
Available-for-sale Securities, Fair Value Disclosure     218,791 190,723 4,075 3,074 300 4,300        
Investments, Amortized Cost Basis 234,027 209,470                    
Investments, Gross Unrealized Gains 41 35                    
Investments, Gross Unrealized Losses (27) (64)                    
Investments $ 234,041 $ 209,441