Condensed Consolidated Balance Sheets (Parenthetical) (USD $) In Thousands, except Share data, unless otherwise specified	6 Months Ended	12 Months Ended
	Sep. 30, 2014	Mar. 31, 2014
Accounts receivable - trade, allowance for doubtful accounts (in dollars)	$ 2,816	$ 2,822
PROPERTY, PLANT AND EQUIPMENT, accumulated depreciation (in dollars)	153,057	109,564
INTANGIBLE ASSETS, accumulated amortization (in dollars)	$ 166,484	$ 116,728
General partner, interest (as a percent)	0.10%	0.10%
General partner, notional units outstanding	88,634	79,420
Limited partners, interest (as a percent)	99.90%	99.90%
Common Units
Units issued	88,545,764	73,421,309
Units outstanding	88,545,764	73,421,309
Subordinated Units
Units issued		5,919,346
Units outstanding		5,919,346