Shareholders' Equity - Components of Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2019	Dec. 31, 2018
Accumulated Other Comprehensive Income (Loss)
Beginning of the period	$ 1,167,537	$ 1,012,164	$ 1,176,339	$ 1,050,557
Other comprehensive income (loss)	(562)	(525)	(3,794)	(4,838)
End of the period	1,297,793	1,132,088	1,297,793	1,132,088
Total
Accumulated Other Comprehensive Income (Loss)
Beginning of the period	(108,930)	(97,768)	(105,698)	(93,455)
End of the period	(109,492)	$ (98,293)	(109,492)	$ (98,293)
Cumulative Translation Adjustment
Accumulated Other Comprehensive Income (Loss)
Beginning of the period			(92,148)
Other comprehensive income (loss)			(2,639)
End of the period	(94,787)		(94,787)
Defined Benefit Plan
Accumulated Other Comprehensive Income (Loss)
Beginning of the period			(13,932)
Other comprehensive income (loss)			(114)
End of the period	(14,046)		(14,046)
Deferred Hedging Losses
Accumulated Other Comprehensive Income (Loss)
Beginning of the period			382
Other comprehensive income (loss)			(1,041)
End of the period	$ (659)		$ (659)