EQUITY AND CASH COMPENSATION UNDER THE PPG AGREEMENTS (Details) - USD ($) $ / shares in Units, $ in Thousands		3 Months Ended		9 Months Ended
	Oct. 01, 2011	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Long-term Purchase Commitment [Line Items]
Percent Of Services Payable In Cash Or Shares		50.00%		50.00%
Issuance of common stock in connection with materials and license agreements (in shares)		0	0	0	0
Research and development expense, cash portion, excluding amounts paid for commercial chemicals		$ 11,434	$ 7,915	$ 32,000	$ 28,639
New OLED Materials Agreement and OLED Materials Agreement [Member]
Long-term Purchase Commitment [Line Items]
New OLED Materials Agreement, automatic renewal term	1 year
New OLED Materials Agreement, termination notice period	1 year
Minimum average closing price of common stock (in dollars per share)		$ 20.00		$ 20.00
Research and development expense, cash portion, excluding amounts paid for commercial chemicals		$ 2,700	$ 378	$ 5,700	$ 7,500
PPG Industries [Member] | New OLED Materials Agreement and OLED Materials Agreement [Member]
Long-term Purchase Commitment [Line Items]
New OLED Materials Agreement, termination notice period	2 years