Earnings per share - Weighted Average Shares Outstanding (Detail) - shares shares in Thousands	12 Months Ended
Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Earnings per share details 1 [abstract]
Weighted average shares outstanding for basic per share	1,087,050	1,086,642	1,086,394
Subscription warrants - indemnification	3,570	3,570	3,570
Deferred stock plan	2,858	2,614	2,602
Weighted average shares outstanding for diluted per share	1,093,478	1,092,826	1,092,566

The weighted average number of ordinary shares outstanding plus the weighted average number of ordinary shares that would be issued on the conversion of all the dilutive potential ordinary shares into ordinary shares. [Refer: Ordinary shares [member]; Weighted average [member]]

No definition available.

Name:	ugp_WeightedAverageSharesDiluted
Namespace Prefix:	ugp_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration