Condensed Consolidated Statement of Changes in Partners' Equity (USD $) In Thousands, except Share data, unless otherwise specified	Total USD ($)	Common units	Accumulated Other Comprehensive Income (Loss) USD ($)	Noncontrolling Interests USD ($)	General Partner USD ($)	Limited Partners Common units USD ($)	Limited Partners Subordinated units USD ($)
BALANCES at Mar. 31, 2013	$ 889,418		$ 24	$ 5,740	$ (50,497)	$ 920,998	$ 13,153
BALANCES (in units) at Mar. 31, 2013						47,703,313	5,919,346
Increase (Decrease) in Partnership Capital
Distributions	(60,623)			(365)	(2,928)	(51,581)	(5,749)
Contributions	2,444			1,940	504
Sales of units in public offerings, net of issuance costs	415,089					415,089
Sales of units in public offerings, net of issuance costs (in units)						14,450,000
Units issued in business combinations, net of offering costs	80,619					80,619
Units issued in business combinations, net of offering costs (in units)						2,860,879
Equity issued pursuant to incentive compensation plan	8,619					8,619
Equity issued pursuant to incentive compensation plan (in units)						282,692
Net income (loss)	(18,440)			134	4,139	(19,439)	(3,274)
Foreign currency translation adjustment	(30)		(30)
BALANCES at Sep. 30, 2013	$ 1,317,096		$ (6)	$ 7,449	$ (48,782)	$ 1,354,305	$ 4,130
BALANCES (in units) at Sep. 30, 2013						65,296,884	5,919,346