Employee Benefit Plans and Postretirement Health Care and Life Insurance Benefits (Amounts in Accumulated Other Comprehensive Income Not Yet Recognized, and Amounts to Be Recognized in Next Fiscal Year) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Mar. 31, 2013
Pension Benefits
Amounts in accumulated other comprehensive income that have not yet been recognized
Net loss arising during the year	$ 12,948
Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Net Prior Service Cost Arising During Period, before Tax	(62)
Net prior service cost during the year	(2,172)
Exchange rate loss recognized during the year	(396)
Total	10,318
Amounts in accumulated other comprehensive income expected to be recognized as components of net periodic benefit cost in next fiscal year
Prior service cost/(credit)	62
Net loss	3,118
Total	3,180
Other Post-Retirement Benefits
Amounts in accumulated other comprehensive income that have not yet been recognized
Net loss arising during the year	1,097
Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Net Prior Service Cost Arising During Period, before Tax	490
Net prior service cost during the year	(642)
Exchange rate loss recognized during the year	(107)
Total	838
Amounts in accumulated other comprehensive income expected to be recognized as components of net periodic benefit cost in next fiscal year
Prior service cost/(credit)	(490)
Net loss	682
Total	$ 192