LONG-TERM DEBT (Details) (USD $)	3 Months Ended					3 Months Ended	0 Months Ended	3 Months Ended								3 Months Ended					6 Months Ended	0 Months Ended	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013	Dec. 31, 2013	Mar. 31, 2014 General Partner [Member]	Jun. 30, 2013 Series A convertible preferred units	Mar. 31, 2014 Prior to Covenant Election [Member]	Apr. 12, 2013 Credit Facility, due November 2017	Mar. 31, 2014 Credit Facility, due November 2017	Mar. 31, 2013 Credit Facility, due November 2017	Mar. 13, 2014 Credit Facility, due November 2017	Jan. 29, 2014 Credit Facility, due November 2017	Dec. 31, 2013 Credit Facility, due November 2017	Jun. 30, 2013 Credit Facility, due November 2017	Mar. 27, 2013 Credit Facility, due November 2017	Nov. 07, 2012 Credit Facility, due November 2017	Mar. 31, 2014 Credit Facility, due November 2017 September 30, 2013	Mar. 31, 2013 Credit Facility, due November 2017 September 30, 2013	Mar. 31, 2014 Letters of credit	Apr. 12, 2013 Letters of credit	Nov. 07, 2012 Letters of credit	Jun. 30, 2012 Credit Agreement, due June 2014	Jan. 29, 2014 Revolving Credit Facility [Member]	Mar. 31, 2014 Scenario, Forecast [Member] Credit Facility, due November 2017 Prior to Covenant Election [Member]	Mar. 31, 2014 Scenario, Forecast [Member] Credit Facility, due November 2017 After Covenant Election [Member]	Mar. 31, 2014 Scenario, Actual [Member] Credit Facility, due November 2017 Prior to Covenant Election [Member]	Mar. 31, 2014 Scenario, Actual [Member] Credit Facility, due November 2017 After Covenant Election [Member]
LONG TERM DEBT
Long-term Debt								$ 170,850,000				$ 267,300,000
unused borrowings										350,000,000.0			350,000,000.0	250,000,000.0	350,000,000.0				50,000,000.0	75,000,000
Fees incurred in connection with the amendment to credit facility							1,500,000				100,000			600,000
Leverage ratio for one quarter							4.25	5.00
Leverage ratio for two consecutive quarters							4.50
Line of Credit Facility, Amount Outstanding				170,900,000														24,500,000
Line of Credit Facility, Remaining Borrowing Capacity								154,700,000
Line of Credit Facility, Average Outstanding Amount	192,400,000	229,800,000
Description of variable rate basis							LIBOR
Basis spread on variable rate (as a percent)							4.50%	2.50%	3.30%												3.25%
Weighted-average interest rate																4.60%	3.50%
Maximum growth capital expenditures for the remainder of 2013							25,000,000.0
Maximum additional growth capital expenditures for the subsequent 18 months ended June 30, 2015							25,000,000.0
Increase in amount deposited by general partner into the Collateral Account							28,000,000.0
Maximum quarterly distributions until the target leverage ratio is achieved (in dollars per share)	$ 0.40						$ 0.40
Total capital infusion					40,000,000
Debt Instrument Covenant Consolidated Senior Secured Leverage Ratio Required to be Maintained upon Exercising One Time Covenant Election																										3.50
Minimum consolidated interest coverage ratio																							2.50	2.50
Debt Instrument Leverage Ratio						5.00
Maximum outstanding borrowings	267,300,000	246,000,000
Debt Instrument, Covenant, Limitation on Acquisition Price, Business Combination																						40,000,000
Maximum adjusted consolidated total leverage ratio																						5.75			4.50	5.25
Long-term debt	$ 170,850,000		$ 267,300,000