Income Taxes Income Tax Provision (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Mar. 31, 2012	Mar. 31, 2011	Mar. 31, 2010
Income Tax Contingency [Line Items]
U.S.	$ (21,923)	$ (51,092)	$ (43,645)
Non-U.S.	76,081	83,941	117,837
Income before income taxes and other items	54,158	32,849	74,192
Income Tax Expense (Benefit), Continuing Operations [Abstract]
Current, Federal	0	472	0
Current, State	0	0	(7,509)
Current, Non-U.S.	31,798	7,346	6,173
Current income tax expense (benefit)	31,798	7,818	(1,336)
Deferred, Federal	0	97,311	(9,271)
Deferred, State	0	631	(631)
Deferred, Non-U.S.	(6,759)	1,700	7,447
Deferred, income tax expense (benefit)	(6,759)	99,642	(2,455)
Total	25,039	107,460	(3,791)
Income Tax Expense (Benefit), Continuing Operations, Income Tax Reconciliation [Abstract]
Tax expense at U.S. statutory rate	18,955	11,497	25,967
Effect of non-U.S. income taxes	(4,712)	(7,322)	(16,309)
Goodwill amortization	0	(4,640)	(8,374)
Change in valuation allowance	1,617	111,679	(3,345)
Increase (decrease) in reserves for uncertain tax positions	3,452	4,489	(8,060)
Exchange effects and currency translation	3,958	(7,120)	5,680
Permanent items	1,769	(1,123)	650
Total	25,039	107,460	(3,791)
Change in valuation allowance	$ 4,558