Borrowings (Components of Interest Expense) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Interest expense, borrowings:
Interest expense	$ 20,762	$ 20,658	$ 39,304	$ 40,579
Capitalized interest	(871)	(220)	(1,422)	(387)
Amortization of transaction costs	748	801	1,491	1,554
Interest expense resulting from derivatives	3,334	3,638	6,700	7,279
Total interest expense	$ 23,973	24,877	$ 46,073	49,025
Write-off of transaction costs related to early extinguishment of debt		298		298
Fees on early extinguishment of debt		3,783		3,783
Fees and amortization on early extinguishment of debt		4,081		4,081
Total	$ 23,973	$ 28,958	$ 46,073	$ 53,106