Unaudited Quarterly Financial Data (Unaudited Quarterly Financial Data) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2020	Mar. 31, 2019	Mar. 31, 2018
Quarterly Financial Information Disclosure [Abstract]
Sales and other operating revenues	$ 632,094	$ 505,049	$ 475,921	$ 296,915	$ 671,723	$ 636,107	$ 539,604	$ 379,719	$ 1,909,979	$ 2,227,153	$ 2,033,947
Gross profit	109,160	92,973	96,029	58,650	119,480	115,430	99,460	72,221
Net income	18,043	29,318	29,747	895	33,692	31,089	34,293	11,060	78,003	110,134	116,168
Net income attributable to Universal Corporation	$ 15,565	$ 25,966	$ 28,077	$ 2,072	$ 31,361	$ 28,135	$ 31,446	$ 13,179	$ 71,680	$ 104,121	$ 105,662
Basic	$ 0.63	$ 1.04	$ 1.12	$ 0.08	$ 1.25	$ 1.12	$ 1.25	$ 0.53	$ 2.87	$ 4.14	$ 4.18
Diluted	0.63	1.04	1.11	0.08	1.24	1.11	1.24	0.52	2.86	4.11	4.14
Common stock, cash dividends declared per share	0.76	0.76	0.76	0.76	0.75	0.75	0.75	0.75	3.04	3.00	$ 2.18
Market price range of common stock, high	58.14	57.06	62.70	60.94	60.67	76.98	71.60	68.25	58.14	60.67
Market price range of common stock, low	$ 38.58	$ 50.27	$ 49.39	$ 51.02	$ 52.60	$ 53.03	$ 55.66	$ 46.40	$ 38.58	$ 52.60