Restructuring and Related Charges (Details) (USD $) In Thousands, unless otherwise specified	6 Months Ended		18 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012
Restructuring Cost and Reserve [Line Items]
Provision	$ 1,200		$ 12,100
Payments and settlements for restructuring	(5,938)	(998)
Fiscal 2012 Restructuring Plan [Member]
Restructuring Cost and Reserve [Line Items]
Balance at March 31, 2012	6,299
Provision	1,213
Payments and settlements for restructuring	(5,938)
Balance at September 30, 2012	1,574		1,574
Severance and employment costs [Member] | Fiscal 2012 Restructuring Plan [Member]
Restructuring Cost and Reserve [Line Items]
Balance at March 31, 2012	5,507
Provision	1,268
Payments and settlements for restructuring	5,661
Balance at September 30, 2012	1,114		1,114
Facilities costs [Member] | Fiscal 2012 Restructuring Plan [Member]
Restructuring Cost and Reserve [Line Items]
Balance at March 31, 2012	297
Provision	(64)
Payments and settlements for restructuring	(145)
Balance at September 30, 2012	88		88
Facilities costs [Member] | Fiscal 2009 Restructuring Plan [Member]
Restructuring Cost and Reserve [Line Items]
Balance at March 31, 2012	495
Provision	9
Payments and settlements for restructuring	132
Balance at September 30, 2012	$ 372		$ 372