Restructuring and Asset Impairment Charges Cash Payments by Year (Details) (USD $)	12 Months Ended
	Mar. 31, 2013	Mar. 31, 2012	Mar. 31, 2011
Restructuring Cost and Reserve [Line Items]
Employee separation and other cash charges (recoveries)	$ (55,000)	$ 246,000	$ 19,337,000
Cash paid 2011	0	0	(13,144,000)
Cash paid 2012	0	(62,000)	(4,417,000)
Cash paid 2013	0	(184,000)	(1,053,000)
Adjustment	55,000	0	(55,000)
Balance at	0	0	668,000
Total cash payments	$ (1,237,000)	$ (4,479,000)	$ (13,144,000)