Accumulated Other Comprehensive Loss (Accumulated Other Comprehensive Loss) (Details) - USD ($) $ in Thousands	3 Months Ended						9 Months Ended
	Nov. 30, 2019	Aug. 31, 2019	May 31, 2019	Nov. 30, 2018	Aug. 31, 2018	May 31, 2018	Nov. 30, 2019	Nov. 30, 2018
Schedule of Accumulated Other Comprehensive Loss [Line Items]
Beginning balance			$ (68,010)				$ (68,010)
Other comprehensive loss before reclassifications							(16,807)
Amounts reclassified from accumulated other comprehensive loss							2,810
Other comprehensive income (loss), net of taxes	$ 9,623	$ (10,424)	(13,196)	$ 298	$ 610	$ (733)	(13,997)	$ 175
Ending balance	(82,007)						(82,007)
Net Unrecognized Actuarial Losses
Schedule of Accumulated Other Comprehensive Loss [Line Items]
Beginning balance			(70,478)				(70,478)
Other comprehensive loss before reclassifications							0
Amounts reclassified from accumulated other comprehensive loss							1,066
Other comprehensive income (loss), net of taxes							1,066
Ending balance	(69,412)						(69,412)
Net Unrecognized Hedge Gains (Losses)
Schedule of Accumulated Other Comprehensive Loss [Line Items]
Beginning balance			$ 2,468				2,468
Other comprehensive loss before reclassifications							(16,807)
Amounts reclassified from accumulated other comprehensive loss							1,744
Other comprehensive income (loss), net of taxes							(15,063)
Ending balance	$ (12,595)						$ (12,595)