CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) (Parenthetical) - USD ($) $ in Thousands	12 Months Ended
	Mar. 31, 2016	Mar. 31, 2015	Mar. 31, 2014
Statement Of Income And Comprehensive Income [Abstract]
Unrealized gains(losses) on available-for-sale securities, tax	$ (239)	$ 0	$ 115
Amortization of loss on derivative contract, tax	77	0	251
Change in supplemental executive retirement plan pension liability, tax	1,264	0	409
Change in Pension Plan minimum liability, tax	1,093	0	763
Change in Other Benefit Plan minimum liability, tax	$ 5,081	$ (769)	$ 1,109