Restructuring (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Mar. 31, 2014	Mar. 31, 2013	Mar. 31, 2012
Restructuring Cost and Reserve [Line Items]
Restructuring charges	$ 14,122	$ 18,719	$ 14,254
Manufacturing and sales office relocation costs
Restructuring Cost and Reserve [Line Items]
Restructuring charges	3,555	2,349	1,920
Personnel reduction costs
Restructuring Cost and Reserve [Line Items]
Restructuring charges	$ 10,567	$ 16,370	$ 12,334