CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) - USD ($) $ in Thousands	12 Months Ended
	Mar. 31, 2016	Mar. 31, 2015	Mar. 31, 2014
Statement Of Income And Comprehensive Income [Abstract]
Net (loss) earnings	$ (160,376)	$ (65,349)	$ 140,255
Other comprehensive income (loss):
Unrealized gains (losses) on available for sale securities, net of tax of ($239), $0 and $115, respectively	(443)	143	213
Amortization of loss on derivative contract, net of tax of $77, $0 and $251, respectively	143	717	466
Change in supplemental executive retirement plan pension liability, net of tax of $1,264, $0 and $409, respectively	2,347	(1,845)	760
Change in pension plan minimum liability, net of tax of $1,093, $0 and $763, respectively	2,029	(5,739)	1,417
Change in other benefit plan minimum liability, net of tax of $5,081, ($769) and $1,109, respectively	9,436	(1,429)	2,060
Total comprehensive (loss) income	$ (146,864)	$ (73,502)	$ 145,171