Earnings per Unit (Details) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended		9 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2012	Dec. 31, 2011
Earnings (loss) per common or subordinated limited partner unit
Net income (loss) attributable to parent equity	$ 40,176	$ 6,090	$ 25,599	$ (6,079)
Loss (income) allocated to general partner	(942)	(6)	(1,731)	6
Net Income (Loss) Attributable to Parent Equity Allocated to Limited Partners	39,234	6,084	23,868	(6,073)
Net income (loss) allocated to:
Common unitholders	34,799	4,412	20,843	(5,111)
Subordinated unitholders	$ 4,435	$ 1,672	$ 3,025	$ (962)
Weighted average common units outstanding - Basic and Diluted	46,364,381	18,699,590	39,288,012	12,491,836
Weighted average subordinated units outstanding - Basic and Diluted	5,919,346	5,919,346	5,919,346	4,929,201
Earnings (loss) per common unit - Basic and Diluted (in dollars per unit)	$ 0.75	$ 0.24	$ 0.53	$ (0.41)
Earnings (loss) per subordinated unit - Basic and Diluted (in dollars per unit)	$ 0.75	$ 0.28	$ 0.51	$ (0.20)
Restricted units that did not cause any dilution (in shares)	1,651,400		1,651,400