FINANCIAL INSTRUMENTS - Roll forward of notional value (Details) (Interest rate swaps, USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011
Interest rate swaps
Notional Amount Of Interest Rate Derivatives [Roll Forward]
Balance, beginning of the period	$ 7,667	$ 11,000
Matured contracts	(7,667)	(3,333)
Balance, end of the period		$ 7,667