Acquisitions (Details 5) (USD $)	6 Months Ended	12 Months Ended	6 Months Ended	12 Months Ended	6 Months Ended	12 Months Ended	6 Months Ended	12 Months Ended											3 Months Ended					3 Months Ended					3 Months Ended								3 Months Ended				0 Months Ended
	Sep. 30, 2013 Buildings and leasehold improvements Minimum	Mar. 31, 2013 Buildings and leasehold improvements Minimum	Sep. 30, 2013 Buildings and leasehold improvements Maximum	Mar. 31, 2013 Buildings and leasehold improvements Maximum	Sep. 30, 2013 Crude oil tanks and related equipment Minimum	Mar. 31, 2013 Crude oil tanks and related equipment Minimum	Sep. 30, 2013 Crude oil tanks and related equipment Maximum	Mar. 31, 2013 Crude oil tanks and related equipment Maximum	Sep. 30, 2013 Pecos	Nov. 01, 2012 Pecos	Mar. 31, 2013 Pecos Estimated as of March 31, 2013	Sep. 30, 2013 Pecos Difference	Sep. 30, 2013 Pecos Trade names	Mar. 31, 2013 Pecos Trade names Estimated as of March 31, 2013	Sep. 30, 2013 Pecos Trade names Difference	Mar. 31, 2013 Pecos Customer relationships Estimated as of March 31, 2013	Sep. 30, 2013 Pecos Customer relationships Difference	Sep. 30, 2013 Pecos Vehicles	Sep. 30, 2013 Pecos Vehicles Minimum	Sep. 30, 2013 Pecos Vehicles Maximum	Mar. 31, 2013 Pecos Vehicles Estimated as of March 31, 2013	Sep. 30, 2013 Pecos Vehicles Difference	Sep. 30, 2013 Pecos Buildings and leasehold improvements	Sep. 30, 2013 Pecos Buildings and leasehold improvements Minimum	Sep. 30, 2013 Pecos Buildings and leasehold improvements Maximum	Mar. 31, 2013 Pecos Buildings and leasehold improvements Estimated as of March 31, 2013	Sep. 30, 2013 Pecos Buildings and leasehold improvements Difference	Sep. 30, 2013 Pecos Crude oil tanks and related equipment	Sep. 30, 2013 Pecos Crude oil tanks and related equipment Minimum	Sep. 30, 2013 Pecos Crude oil tanks and related equipment Maximum	Mar. 31, 2013 Pecos Crude oil tanks and related equipment Estimated as of March 31, 2013	Sep. 30, 2013 Pecos Crude oil tanks and related equipment Difference	Sep. 30, 2013 Pecos Land	Mar. 31, 2013 Pecos Land Estimated as of March 31, 2013	Sep. 30, 2013 Pecos Land Difference	Sep. 30, 2013 Pecos Other	Sep. 30, 2013 Pecos Other Minimum	Sep. 30, 2013 Pecos Other Maximum	Mar. 31, 2013 Pecos Other Estimated as of March 31, 2013	Sep. 30, 2013 Pecos Other Difference	Nov. 12, 2012 Pecos Call agreement Common units	Nov. 01, 2012 Pecos Call agreement Common units Minimum	Nov. 01, 2012 Pecos Call agreement Common units Maximum
Acquisitions
Amount of additional consideration payable										$ 10,200,000
Number of common units issued to acquire business (in shares)																																									1,834,414
Estimated fair value of the assets acquired and liabilities assumed
Accounts receivable - trade									73,609,000		73,704,000	(95,000)
Inventories									1,903,000		1,903,000
Other current assets									1,426,000		1,426,000
Property, plant and equipment																		22,097,000			19,193,000	2,904,000	1,339,000			1,248,000	91,000	1,099,000			913,000	186,000	223,000	224,000	(1,000)	36,000			177,000	(141,000)
Useful life of property, plant and equipment	5 years	5 years	30 years	30 years	2 years	2 years	30 years	30 years											5 years	10 years				5 years	30 years				2 years	15 years							3 years	5 years
Intangible assets													900,000	1,000,000	(100,000)	8,000,000	(8,000,000)
Goodwill									91,747,000		86,661,000	5,086,000
Trade accounts payable									(50,795,000)		(50,808,000)	13,000
Accrued expenses									(963,000)		(1,020,000)	57,000
Long-term debt									(10,234,000)		(10,234,000)
Fair value of net assets acquired									132,387,000		132,387,000
Consideration paid for acquisition
Cash paid, net of cash acquired									87,444,000
Value of common units issued									44,943,000																																45,000,000	45,000,000	60,000,000
Total consideration paid									$ 132,387,000