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Post-employment Benefits - Summary of Main Assumptions Used in Actuarial Valuation of Retirement Plans (Detail)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Disclosure of defined benefit plans [line items]
Discount rate	9.72%	9.98%	10.24%
Mortality table	AT-2000	AT-2000	AT-2000
Turnover	Itaú Experience 2008/2010	Itaú Experience 2008/2010	Exp.Itaú 2008/2010
Growth of the pension fund benefits	4.00%	4.00%	4.00%
Inflation	4.00%	4.00%	4.00%
Actuarial method	Projected Unit Credit	Projected Unit Credit	Cred.Unit.Projet.
Bottom of range [member]
Disclosure of defined benefit plans [line items]
Future salary growth	4.00%	5.04%	5.04%
Top of range [member]
Disclosure of defined benefit plans [line items]
Future salary growth	7.12%	7.12%	7.12%

X

- Definition

The discount rate used as the significant actuarial assumption to determine the present value of a defined benefit obligation. [Refer: Defined benefit obligation, at present value; Actuarial assumptions [member]]

+ References

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The expected rate of inflation that is used as a significant actuarial assumption to determine the present value of a defined benefit obligation. [Refer: Defined benefit plans [member]; Defined benefit obligation, at present value; Actuarial assumptions [member]]

+ References

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The expected rate of increases in pension that is used as a significant actuarial assumption to determine the present value of a defined benefit obligation. [Refer: Defined benefit plans [member]; Defined benefit obligation, at present value; Actuarial assumptions [member]]

+ References

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The expected rate of salary increases used as a significant actuarial assumption to determine the present value of a defined benefit obligation. [Refer: Defined benefit plans [member]; Defined benefit obligation, at present value; Actuarial assumptions [member]]

+ References

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The description of the methods and assumptions used when preparing a sensitivity analysis for significant actuarial assumptions. [Refer: Actuarial assumptions [member]]

+ References

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Line items represent concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes of the table.

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Description of Mortality

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Turnover

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