PARTNERS' CAPITAL AND DISTRIBUTIONS (Details) (USD $) In Millions, except Share data, unless otherwise specified	1 Months Ended		3 Months Ended	9 Months Ended	1 Months Ended		1 Months Ended
	May 31, 2013 item	Sep. 01, 2013 MMBbls	Sep. 30, 2013 LP Units Equity Distribution Agreements	Sep. 30, 2013 LP Units Equity Distribution Agreements	Jan. 31, 2013 LP Units Secondary public offering	Jan. 31, 2013 LP Units Underwriter option	May 31, 2013 LP Units Wells Fargo Securities, LLC Equity Distribution Agreements	May 31, 2013 LP Units Barclays Capital Inc. Equity Distribution Agreements	May 31, 2013 LP Units SunTrust Robinson Humphrey, Inc. Equity Distribution Agreements	May 31, 2013 LP Units UBS Securities, LLC Equity Distribution Agreements	Sep. 30, 2013 Class B Units	Sep. 01, 2013 Class B Units	Dec. 31, 2012 Class B Units
Partner's capital and distributions
Units outstanding											0	8,500,000	7,975,000
Conversion ratio		1
Maximum incremental storage capacity, unit conversion threshold		4
Minimum incremental storage capacity, unit conversion threshold		4
Number of separate equity distribution agreements	4
Gross proceeds from sale of LP Units allowed under agreement							$ 300.0	$ 300.0	$ 300.0	$ 300.0
Public offering, LP units issued			500,000	500,000	6,000,000	900,000
Amount per share or per unit of equity securities issued by non-development stage entity					$ 52.54
Aggregate compensation expense paid to the agents under the Equity Distribution Agreements			0.1	0.4
Total gross proceeds from public offering				33.1	362.5
Underwriting fees and estimated offering expenses					$ 13.3