Subsidiary guarantee information - Comprehensive income related (Details 2) - CHF (SFr) SFr in Millions	12 Months Ended
Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Comprehensive income
Net income/(loss)	SFr 3,095	SFr 1,722	SFr (1,228)
Gains/(losses) on cash flow hedges	86	(7)	(35)
Foreign currency translation	(995)	(321)	(1,015)
Unrealized gains/(losses) on securities	21	(18)	(13)
Actuarial gains/(losses)	(24)	31	21
Net prior service cost	1	(10)	0
Other comprehensive income/(loss), net of tax	(2,649)	1,117	(2,726)
Comprehensive income/(loss)	446	2,839	(3,954)
Comprehensive income/(loss) attributable to noncontrolling interests	7	(3)	(9)
Comprehensive income/(loss) attributable to shareholders	439	2,842	(3,945)
Gains/(losses) on liabilities related to credit risk	SFr (1,738)	SFr 1,442	SFr (1,684)

Amount after tax of increase (decrease) in equity from transactions and other events and circumstances from net income and other comprehensive income, attributable to parent entity. Excludes changes in equity resulting from investments by owners and distributions to owners.

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Amount after tax of increase (decrease) in equity from transactions and other events and circumstances from net income (loss) and other comprehensive income (loss), attributable to noncontrolling interests. Excludes changes in equity resulting from investments by owners and distributions to owners.

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Amount after tax of increase (decrease) in equity from transactions and other events and circumstances from net income and other comprehensive income. Excludes changes in equity resulting from investments by owners and distributions to owners.

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Amount, after tax, of cost (credit) of benefit change attributable to participants' prior service from plan amendment or plan initiation of defined benefit plan, that has not been recognized in net periodic benefit cost (credit).

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Amount after tax and reclassification adjustments of gain (loss) on foreign currency translation adjustments, foreign currency transactions designated and effective as economic hedges of a net investment in a foreign entity and intra-entity foreign currency transactions that are of a long-term-investment nature.

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