FINANCIAL INSTRUMENTS (Tables)

12 Months Ended

Dec. 31, 2012

Financial Instruments [Abstract]

Schedule of derivative instrument showing notional value of interest rate swaps

Balance, December 31, 2010	$	11,000
Matured contracts		(3,333	)
Balance, December 31, 2011	$	7,667
Matured contracts		(7,667	)
Balance, December 31, 2012	$	—

Schedule of other derivatives not designated as hedging Instruments included in financial statements

			December 31,
Type	Maturity	Balance Sheet Location	2012		2011
Interest rate swaps	June 2012	Other current liabilities	$	—	$	57

Schedule of derivatives not designated as hedging instruments included in condensed consolidated statement of comprehensive earnings

									Location of
	Year Ended December 31,								(Gain) Loss
	2012			2011				2010	Recognized in Income
Periodic settlements	$	60		$	145		$	192	Interest expense
Change in fair value	$	(57	)	$	(130	)	$	107	Interest expense

Schedule of available-for-sale securities

	December 31,
	2012									2011
	Amortized Cost			Gross Unrealized Gain			Estimated Fair Value			Amortized Cost			Gross Unrealized Gain (Loss)				Estimated Fair Value
U.S. Treasury and other U.S. government securities		$	4,577		$	4		$	4,581		$	4,308		$	6			$	4,314
State and municipal securities			218			1			219			689			4				693
Corporate and other securities			6,489			30			6,519			6,654			(36	)			6,618
Total		$	11,284		$	35		$	11,319		$	11,651		$	(26	)		$	11,625

Schedule of estimated fair value of marketable securities by contractual maturity

Due in one year or less	$	4,436
Due after one year through five years		6,883
Total	$	11,319

Schedule of fair value measured on recurring basis

	Quoted  Prices in  Active Markets (Level 1)		Significant  Other  Observable Inputs (Level 2)			Significant Unobservable Inputs (Level 3)		Total
December 31, 2012
Money market funds	$	477	$	—		$	—	$	477
Marketable securities		11,319		—			—		11,319
Total assets	$	11,796	$	—		$	—	$	11,796
December 31, 2011
Money market funds	$	8,483	$	—		$	—	$	8,483
Marketable securities		11,625		—			—		11,625
Total assets	$	20,108	$	—		$	—	$	20,108
Interest rate swaps liability	$	—	$	(57	)	$	—	$	(57	)