Schedule I - Condensed Financial Information Of AMERCO (Statements of Comprehensive Income) (Details) - USD ($) $ in Thousands	12 Months Ended
	Mar. 31, 2020	Mar. 31, 2019	Mar. 31, 2018
Net earnings	$ 442,048	$ 370,857	$ 790,583
Amerco [Member]
Net earnings	442,048	370,857	790,583
Other comprehensive income (loss)	101,350	(62,075)	37,873
Total comprehensive income	$ 543,398	$ 308,782	$ 828,456