Shareholders' Equity - Components of Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2018	Dec. 31, 2017
Accumulated Other Comprehensive Income (Loss)
Beginning of the period			$ 1,050,557	$ 856,111
Other comprehensive income (loss)	$ (525)	$ 3,636	(4,838)	5,539
End of the period	1,132,088	1,007,236	1,132,088	1,007,236
Total
Accumulated Other Comprehensive Income (Loss)
Beginning of the period			(93,455)	(100,706)
End of the period	(98,293)	$ (95,167)	(98,293)	$ (95,167)
Cumulative Translation Adjustment
Accumulated Other Comprehensive Income (Loss)
Beginning of the period			(83,848)
Other comprehensive income (loss)			(8,252)
End of the period	(92,100)		(92,100)
Defined Benefit Plan
Accumulated Other Comprehensive Income (Loss)
Beginning of the period			(6,398)
Other comprehensive income (loss)			(100)
End of the period	(6,498)		(6,498)
Deferred Hedging Losses
Accumulated Other Comprehensive Income (Loss)
Beginning of the period			(3,209)
Other comprehensive income (loss)			3,514
End of the period	$ 305		$ 305