Condensed Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Jun. 30, 2015	Mar. 31, 2015
Accounts receivable - trade, allowance for doubtful accounts (in dollars)	$ 4,827	$ 4,367
PROPERTY, PLANT AND EQUIPMENT, accumulated depreciation (in dollars)	236,863	202,959
INTANGIBLE ASSETS, accumulated amortization (in dollars)	$ 248,497	$ 220,517
General partner interest (as a percent)	0.10%	0.10%
General partner, notional units outstanding	104,286	103,899
Limited partners, interest (as a percent)	99.90%	99.90%
Common Units
Units issued	104,181,253	103,794,870
Units outstanding	104,181,253	103,794,870