LONG-TERM DEBT AND NOTES PAYABLE - Narrative (Details) (USD $)	9 Months Ended		12 Months Ended		0 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Dec. 31, 2013	Dec. 31, 2012	Sep. 02, 2014 Line of Credit	Sep. 30, 2014 Line of Credit	Sep. 02, 2014 Line of Credit Extension	Sep. 30, 2014 Letter of Credit	Sep. 30, 2014 Swingline
Debt Instrument [Line Items]
Line of credit facility, short-term, authorized amount	$ 35,000,000
Repayments of lines of credit					15,000,000
Debt issued, maturity term					5 years
Number of extensions permitted under credit agreement							2
Extension period under credit agreement					1 year
Debt percentage to capitalization as financial covenants							70.00%
Ratio of Indebtedness to Net Capital						0.240
Line of credit facility borrowing capacity	150,000,000.0							15,000,000.0	15,000,000.0
Additional increase in borrowing capacity available	50,000,000.0
Interest expense	$ 11,500,000	$ 11,700,000	$ 15,600,000	$ 16,300,000