Restructuring Costs (Narrative) (Details) - USD ($) $ in Thousands	12 Months Ended
	Mar. 31, 2020	Mar. 31, 2019	Mar. 31, 2018
Restructuring Cost and Reserve [Line Items]
Goodwill Impairment	$ 0	$ 889
Restructuring and impairment costs	7,543	20,304	$ 0
Africa
Restructuring Cost and Reserve [Line Items]
Employee termination benefits	1,800
Impairment of Long-Lived Assets Held-for-use	1,300
NORTH CAROLINA
Restructuring Cost and Reserve [Line Items]
Employee termination benefits	$ 3,400
Non-US [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and impairment costs		900
Tanzania
Restructuring Cost and Reserve [Line Items]
Employee termination benefits		4,000
Impairment of Long-Lived Assets Held-for-use		14,600
Goodwill Impairment		$ 900