Unaudited Quarterly Financial Data (Unaudited Quarterly Financial Data) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2019	Mar. 31, 2018	Mar. 31, 2017
Quarterly Financial Information Disclosure [Abstract]
Sales and other operating revenues	$ 671,723	$ 636,107	$ 539,604	$ 379,719	$ 607,496	$ 653,581	$ 488,248	$ 284,622	$ 2,227,153	$ 2,033,947	$ 2,071,218
Gross profit	119,480	115,430	99,460	72,221	116,497	108,518	93,076	53,857
Net income	33,692	31,089	34,293	11,060	34,322	50,219	28,306	3,321	110,134	116,168	112,506
Net income attributable to Universal Corporation	$ 31,361	$ 28,135	$ 31,446	$ 13,179	$ 30,518	$ 45,400	$ 26,167	$ 3,577	104,121	105,662	106,304
Earnings available to Universal Corporation common shareholders									$ 104,121	$ 105,662	$ 20,890
Basic	$ 1.25	$ 1.12	$ 1.25	$ 0.53	$ 1.21	$ 1.80	$ 1.03	$ 0.14	$ 4.14	$ 4.18	$ 0.89
Diluted	1.24	1.11	1.24	0.52	1.20	1.78	1.02	0.14	4.11	4.14	0.88
Preferred stock, cash dividends declared per share	0.00	0.00	0.00	0.00	0.00	0.00	0.00	0.00	0.00	0.00	50.63
Common stock, cash dividends declared per share	0.75	0.75	0.75	0.75	0.55	0.55	0.54	0.54	3.00	2.18	$ 2.14
Market price range of common stock, high	60.67	76.98	71.60	68.25	53.85	60.45	65.90	75.70	60.67	53.85
Market price range of common stock, low	$ 52.60	$ 53.03	$ 55.66	$ 46.40	$ 45.95	$ 52.05	$ 55.00	$ 63.15	$ 52.60	$ 45.95