Consolidated Statement of Comprehensive Income (Parenthetical) $ in Millions	12 Months Ended
Dec. 31, 2020 USD ($)
Statement Of Comprehensive Income [Line Items]
Change of the foreign exchange rate of the Swiss franc against the US dollar	9.00%
Change of the foreign exchange rate of the euro against the US dollar	9.00%
Gains / (losses) on defined benefit plans, before tax	$ (327)
Major plans
Statement Of Comprehensive Income [Line Items]
Gains / (losses) on defined benefit plans, before tax	(323)
Swiss pension plan
Statement Of Comprehensive Income [Line Items]
Gains / (losses) on defined benefit plans, before tax	(276)
Additional employer contributions paid to employees retirement assets	235
UK pension plan
Statement Of Comprehensive Income [Line Items]
Gains / (losses) on defined benefit plans, before tax	$ (61)
UBS AG
Statement Of Comprehensive Income [Line Items]
Change of the foreign exchange rate of the Swiss franc against the US dollar	9.00%
Change of the foreign exchange rate of the euro against the US dollar	9.00%
Gains / (losses) on defined benefit plans, before tax	$ (222)
UBS AG \| Major plans
Statement Of Comprehensive Income [Line Items]
Gains / (losses) on defined benefit plans, before tax	(219)
UBS AG \| Swiss pension plan
Statement Of Comprehensive Income [Line Items]
Gains / (losses) on defined benefit plans, before tax	(172)
Additional employer contributions paid to employees retirement assets	143
UBS AG \| UK pension plan
Statement Of Comprehensive Income [Line Items]
Gains / (losses) on defined benefit plans, before tax	$ (61)

The amount of other comprehensive income, before tax, related to gains (losses) on remeasurements of defined benefit plans, which comprise actuarial gains and losses; the return on plan assets, excluding amounts included in net interest on the net defined benefit liability (asset); and any change in the effect of the asset ceiling, excluding amounts included in net interest on the net defined benefit liability (asset). [Refer: Other comprehensive income, before tax; Defined benefit plans [member]; Plan assets [member]; Net defined benefit liability (asset)]

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
-Number 1
-IssueDate 2019-01-01
-Paragraph 91
-Subparagraph b
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=1&code=ifrs-tx-2019-en-r&anchor=para_91_b&doctype=Standard
-URIDate 2019-03-27

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
-Number 1
-IssueDate 2019-01-01
-Paragraph 7
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=1&code=ifrs-tx-2019-en-r&anchor=para_7&doctype=Standard
-URIDate 2019-03-27

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