FAIR VALUE MEASUREMENTS (Narrative) (Details)	3 Months Ended
	Mar. 31, 2016 USD ($) item	Mar. 31, 2015 USD ($)
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Number of Rabbi Trusts established | item	2
Net gains of the Rabbi Trust investments	$ 82,000	$ 807,000
Unrealized net gains (losses) of the Rabbi Trust investments	(1,024,000)	646,000
Rabbi Trust asset value, decrease	6,897,000
Loss on impairment of long-lived assets	9,646,000	$ 0
Nonrecurring [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Loss on impairment of long-lived assets	9,646,000
Nonrecurring [Member] | Level 2 [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets subject to fair value measurement on a nonrecurring basis	$ 0