Significant Accounting Policies Other Comprehensive Income (Loss) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Mar. 31, 2015	Mar. 31, 2014	Mar. 31, 2013
Other Comprehensive Income (Loss)
Beginning Balance	$ (38,101)
Other comprehensive losses, net of tax	(28,060)	17,091	(16,519)
Ending Balance	(66,161)	(38,101)
Currency Translation Adjustment [Member]
Other Comprehensive Income (Loss)
Beginning Balance	(1,640)	(5,724)	(2,922)
Other comprehensive losses before reclassifications	(12,514)	4,084	(2,802)
Amounts reclassified to net income, net of tax	0	0	0
Other comprehensive losses, net of tax	(12,514)	4,084	(2,802)
Ending Balance	(14,154)	(1,640)	(5,724)
Pensions, Net of Tax [Member]
Other Comprehensive Income (Loss)
Beginning Balance	(36,461)	(49,468)	(35,751)
Other comprehensive losses before reclassifications	(16,257)	10,129	(13,491)
Amounts reclassified to net income, net of tax	711	2,878	(226)
Other comprehensive losses, net of tax	(15,546)	13,007	(13,717)
Ending Balance	(52,007)	(36,461)	(49,468)
Accumulated Other Comprehensive Loss [Member]
Other Comprehensive Income (Loss)
Beginning Balance	(38,101)	(55,192)	(38,673)
Other comprehensive losses before reclassifications	(28,771)	14,213	(16,293)
Amounts reclassified to net income, net of tax	711	2,878	(226)
Other comprehensive losses, net of tax	(28,060)	17,091	(16,519)
Ending Balance	$ (66,161)	$ (38,101)	$ (55,192)