Significant Accounting Policies Other Comprehensive Income (Loss) (Details) - USD ($) $ in Thousands	12 Months Ended
	Mar. 31, 2016	Mar. 31, 2015	Mar. 31, 2014
Other Comprehensive Income (Loss)
Beginning Balance	$ (66,386)
Other comprehensive losses, net of tax	12,545	$ (28,060)	$ 17,091
Ending Balance	(53,848)	(66,386)
Currency Translation Adjustment [Member]
Other Comprehensive Income (Loss)
Beginning Balance	(14,154)	(1,640)	(5,724)
Other comprehensive losses before reclassifications	108	(12,514)	4,084
Amounts reclassified to net income, net of tax	0	0	0
Other comprehensive losses, net of tax	108	(12,514)	4,084
Ending Balance	(14,046)	(14,154)	(1,640)
Pensions, Net of Tax [Member]
Other Comprehensive Income (Loss)
Beginning Balance	(52,232)	(36,686)	(49,693)
Other comprehensive losses before reclassifications	7,811	(16,257)	10,129
Amounts reclassified to net income, net of tax	4,619	711	2,878
Other comprehensive losses, net of tax	12,430	(15,546)	13,007
Ending Balance	(39,802)	(52,232)	(36,686)
Accumulated Other Comprehensive Income (Loss) [Member]
Other Comprehensive Income (Loss)
Beginning Balance	(66,386)	(38,326)	(55,417)
Other comprehensive losses before reclassifications	7,919	(28,771)	14,213
Amounts reclassified to net income, net of tax	4,619	711	2,878
Other comprehensive losses, net of tax	12,538	(28,060)	17,091
Ending Balance	$ (53,848)	$ (66,386)	$ (38,326)