Additional Consolidated Balance Sheets Information Level 4 (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2011	Mar. 31, 2011
Employee-related Liabilities	$ 13,629	$ 16,160
Accrued Vacation	7,638	6,379
Accrued Bonuses	413	13,925
Accrued Liabilities for Commissions, Expense and Taxes	8,823	11,985
Other Postretirement Benefits Payable	3,274	3,274
Pension and Other Postretirement and Postemployment Benefit Plans, Liabilities	480	528
Employee-related Liabilities, Current	34,257	52,251
Deferred Revenue	46,938	34,396
Self Insurance Reserve, Current	3,074	3,610
Accrued Sales Commission	8,773	7,354
Product Warranty Accrual	10,234	7,509
Accrued Liabilities	90,729	73,831
Self Insurance Reserve, Noncurrent	10,233	10,233
Other Postretirement Benefits Payable, Noncurrent	18,603	20,526
Defined Benefit Pension Plan, Liabilities, Noncurrent	5,595	8,006
Pension and Other Postretirement and Postemployment Benefit Plans, Liabilities, Noncurrent	4,061	3,897
Accrued Income Taxes, Noncurrent	6,432	9,140
Other Liabilities	9,642	4,810
Other Accrued Liabilities	21,710	20,962
Other Liabilities, Noncurrent	$ 54,566	$ 56,612