Debt (Details 2) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Mar. 31, 2014	Mar. 31, 2013	Mar. 31, 2012
Interest expense
Contractual interest expense	$ 37,366	$ 37,193	$ 24,967
Amortization of debt issuance costs	1,704	1,704	1,081
Amortization of debt (premium) discount	105	(183)	1,742
Imputed interest on acquisition related obligations	1,787	2,617	777
Total interest expense	$ 40,962	$ 41,331	$ 28,567