Financial risk management - Summary of Sensitivity Analysis on Interest Rates on Loans and Borrowings (Detail) R$ in Thousands	12 Months Ended
	Dec. 31, 2019 BRL (R$)
Probable [member]
Disclosure of sensitivity analysis on income for the period assuming increase and decrease in interest rates [Line Items]
Exposure interest rate	R$ (1,874,184)
Probable [member] | Cash and cash equivalents [member]
Disclosure of sensitivity analysis on income for the period assuming increase and decrease in interest rates [Line Items]
Exposure interest rate	341,188
Probable [member] | Marketable securities [member]
Disclosure of sensitivity analysis on income for the period assuming increase and decrease in interest rates [Line Items]
Exposure interest rate	137,082
Probable [member] | Consideration asset [member]
Disclosure of sensitivity analysis on income for the period assuming increase and decrease in interest rates [Line Items]
Exposure interest rate	(930)
Probable [member] | Restricted cash [member]
Disclosure of sensitivity analysis on income for the period assuming increase and decrease in interest rates [Line Items]
Exposure interest rate	6,508
Probable [member] | Leases [member]
Disclosure of sensitivity analysis on income for the period assuming increase and decrease in interest rates [Line Items]
Exposure interest rate	(486,172)
Probable [member] | Loans, borrowings and debentures [member]
Disclosure of sensitivity analysis on income for the period assuming increase and decrease in interest rates [Line Items]
Exposure interest rate	(1,704,255)
Probable [member] | Other financial liabilities [member]
Disclosure of sensitivity analysis on income for the period assuming increase and decrease in interest rates [Line Items]
Exposure interest rate	(167,605)
25% [member]
Disclosure of sensitivity analysis on income for the period assuming increase and decrease in interest rates [Line Items]
Exposure interest rate	(772,726)
25% [member] | Cash and cash equivalents [member]
Disclosure of sensitivity analysis on income for the period assuming increase and decrease in interest rates [Line Items]
Exposure interest rate	63,239
25% [member] | Marketable securities [member]
Disclosure of sensitivity analysis on income for the period assuming increase and decrease in interest rates [Line Items]
Exposure interest rate	34,271
25% [member] | Consideration asset [member]
Disclosure of sensitivity analysis on income for the period assuming increase and decrease in interest rates [Line Items]
Exposure interest rate	33,426
25% [member] | Restricted cash [member]
Disclosure of sensitivity analysis on income for the period assuming increase and decrease in interest rates [Line Items]
Exposure interest rate	1,627
25% [member] | Leases [member]
Disclosure of sensitivity analysis on income for the period assuming increase and decrease in interest rates [Line Items]
Exposure interest rate	(2,636)
25% [member] | Derivative financial instruments [member]
Disclosure of sensitivity analysis on income for the period assuming increase and decrease in interest rates [Line Items]
Exposure interest rate	(1,110,374)
25% [member] | Loans, borrowings and debentures [member]
Disclosure of sensitivity analysis on income for the period assuming increase and decrease in interest rates [Line Items]
Exposure interest rate	249,622
25% [member] | Other financial liabilities [member]
Disclosure of sensitivity analysis on income for the period assuming increase and decrease in interest rates [Line Items]
Exposure interest rate	(41,901)
50% [member]
Disclosure of sensitivity analysis on income for the period assuming increase and decrease in interest rates [Line Items]
Exposure interest rate	(1,310,070)
50% [member] | Cash and cash equivalents [member]
Disclosure of sensitivity analysis on income for the period assuming increase and decrease in interest rates [Line Items]
Exposure interest rate	121,286
50% [member] | Marketable securities [member]
Disclosure of sensitivity analysis on income for the period assuming increase and decrease in interest rates [Line Items]
Exposure interest rate	68,541
50% [member] | Consideration asset [member]
Disclosure of sensitivity analysis on income for the period assuming increase and decrease in interest rates [Line Items]
Exposure interest rate	66,853
50% [member] | Restricted cash [member]
Disclosure of sensitivity analysis on income for the period assuming increase and decrease in interest rates [Line Items]
Exposure interest rate	3,254
50% [member] | Leases [member]
Disclosure of sensitivity analysis on income for the period assuming increase and decrease in interest rates [Line Items]
Exposure interest rate	(5,272)
50% [member] | Derivative financial instruments [member]
Disclosure of sensitivity analysis on income for the period assuming increase and decrease in interest rates [Line Items]
Exposure interest rate	(2,015,409)
50% [member] | Loans, borrowings and debentures [member]
Disclosure of sensitivity analysis on income for the period assuming increase and decrease in interest rates [Line Items]
Exposure interest rate	534,480
50% [member] | Other financial liabilities [member]
Disclosure of sensitivity analysis on income for the period assuming increase and decrease in interest rates [Line Items]
Exposure interest rate	(83,803)
-25% [member]
Disclosure of sensitivity analysis on income for the period assuming increase and decrease in interest rates [Line Items]
Exposure interest rate	809,516
-25% [member] | Cash and cash equivalents [member]
Disclosure of sensitivity analysis on income for the period assuming increase and decrease in interest rates [Line Items]
Exposure interest rate	(54,722)
-25% [member] | Marketable securities [member]
Disclosure of sensitivity analysis on income for the period assuming increase and decrease in interest rates [Line Items]
Exposure interest rate	(34,271)
-25% [member] | Consideration asset [member]
Disclosure of sensitivity analysis on income for the period assuming increase and decrease in interest rates [Line Items]
Exposure interest rate	(33,426)
-25% [member] | Restricted cash [member]
Disclosure of sensitivity analysis on income for the period assuming increase and decrease in interest rates [Line Items]
Exposure interest rate	(1,627)
-25% [member] | Leases [member]
Disclosure of sensitivity analysis on income for the period assuming increase and decrease in interest rates [Line Items]
Exposure interest rate	2,636
-25% [member] | Derivative financial instruments [member]
Disclosure of sensitivity analysis on income for the period assuming increase and decrease in interest rates [Line Items]
Exposure interest rate	1,138,647
-25% [member] | Loans, borrowings and debentures [member]
Disclosure of sensitivity analysis on income for the period assuming increase and decrease in interest rates [Line Items]
Exposure interest rate	(249,622)
-25% [member] | Other financial liabilities [member]
Disclosure of sensitivity analysis on income for the period assuming increase and decrease in interest rates [Line Items]
Exposure interest rate	41,901
-50% [member]
Disclosure of sensitivity analysis on income for the period assuming increase and decrease in interest rates [Line Items]
Exposure interest rate	1,483,113
-50% [member] | Cash and cash equivalents [member]
Disclosure of sensitivity analysis on income for the period assuming increase and decrease in interest rates [Line Items]
Exposure interest rate	(114,033)
-50% [member] | Marketable securities [member]
Disclosure of sensitivity analysis on income for the period assuming increase and decrease in interest rates [Line Items]
Exposure interest rate	(68,541)
-50% [member] | Consideration asset [member]
Disclosure of sensitivity analysis on income for the period assuming increase and decrease in interest rates [Line Items]
Exposure interest rate	(66,853)
-50% [member] | Restricted cash [member]
Disclosure of sensitivity analysis on income for the period assuming increase and decrease in interest rates [Line Items]
Exposure interest rate	(3,254)
-50% [member] | Leases [member]
Disclosure of sensitivity analysis on income for the period assuming increase and decrease in interest rates [Line Items]
Exposure interest rate	5,272
-50% [member] | Derivative financial instruments [member]
Disclosure of sensitivity analysis on income for the period assuming increase and decrease in interest rates [Line Items]
Exposure interest rate	2,181,199
-50% [member] | Loans, borrowings and debentures [member]
Disclosure of sensitivity analysis on income for the period assuming increase and decrease in interest rates [Line Items]
Exposure interest rate	(534,480)
-50% [member] | Other financial liabilities [member]
Disclosure of sensitivity analysis on income for the period assuming increase and decrease in interest rates [Line Items]
Exposure interest rate	R$ 83,803