Significant Accounting Policies (As Restated) Other Comprehensive Income (Loss) - Reclassifications out of Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Thousands	12 Months Ended
	Mar. 31, 2015	Mar. 31, 2014	Mar. 31, 2013
Accounting Policies [Abstract]
Actuarial loss	$ 3,092	$ 4,436	$ 1,437
Amortization of prior service cost (credit)	(2,213)	(1,369)	(1,549)
Deferred income tax benefit	(168)	(189)	(114)
Amounts reclassified from accumulated other comprehensive income (loss) to net income (loss)	$ 711	$ 2,878	$ (226)