Revenue from Contracts with Customers Revenue from Contract with Customers (Narrative) (Details) - USD ($)	12 Months Ended
	Mar. 31, 2022	Mar. 31, 2021	Mar. 31, 2020
Five largest customers [Member]
Revenues	$ 0.60
Imperial Tobacco Group Plc [Member]
Revenues	380,000,000	$ 340,000,000	$ 320,000,000
Philip Morris International Inc [Member]
Revenues	320,000,000	460,000,000	500,000,000
British American Tobacco Plc [Member]
Revenues	$ 260,000,000	$ 210,000,000	$ 190,000,000