Employee Benefits Net Periodic Pension Costs (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Mar. 31, 2012	Mar. 31, 2011	Mar. 31, 2010
U.S. Pension Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 1,807	$ 2,113	$ 1,666
Interest cost	4,782	4,879	5,352
Expected return on plan assets	(3,663)	(3,190)	(2,730)
Amortization of actuarial (gains) losses	914	1,066	(634)
Amortization of prior service (credit) cost	88	4	(194)
Curtailment loss (gain)	0	0	0
Special termination benefits	0	259	0
Effects of settlement	0	0	0
Net periodic pension cost	3,928	5,131	3,460
Non-U.S. Pension Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	362	1,108	1,969
Interest cost	3,410	3,951	3,784
Expected return on plan assets	(2,859)	(2,567)	(1,824)
Amortization of actuarial (gains) losses	247	276	639
Amortization of prior service (credit) cost	16	19	19
Curtailment loss (gain)	(4,989)	0	0
Special termination benefits	956	1,012	11
Effects of settlement	0	(56)	(17)
Net periodic pension cost	$ (2,857)	$ 3,743	$ 4,581