DUE TO BANKS AND CORRESPONDENTS - Summary of detailed information of deposits from banks (Details)
S/ in Thousands, $ in Millions
Dec. 31, 2019
USD ($)
Dec. 31, 2019
PEN (S/)
Dec. 31, 2018
USD ($)
Dec. 31, 2018
PEN (S/)
Jan. 31, 2018
USD ($)
International funds and others [Member]          
Disclosure Of Deposits From Banks Explanatory [Line Items]          
Borrowings   S/ 5,654,014   S/ 5,460,725  
Bank of America, N.A. [Member]          
Disclosure Of Deposits From Banks Explanatory [Line Items]          
Borrowings | $     $ 150.0    
Bank of America, N.A. [Member] | International funds and others [Member]          
Disclosure Of Deposits From Banks Explanatory [Line Items]          
Borrowings $ 300.0 994,200 150.0 505,950  
Sumitomo Mitsui Banking Corporation [Member]          
Disclosure Of Deposits From Banks Explanatory [Line Items]          
Borrowings | $     100.0    
Sumitomo Mitsui Banking Corporation [Member] | International funds and others [Member]          
Disclosure Of Deposits From Banks Explanatory [Line Items]          
Borrowings 297.0 984,258 100.0 337,300  
Wells Fargo Bank [Member]          
Disclosure Of Deposits From Banks Explanatory [Line Items]          
Borrowings | $     250.0    
Wells Fargo Bank [Member] | International funds and others [Member]          
Disclosure Of Deposits From Banks Explanatory [Line Items]          
Borrowings 190.0 730,074 [1] 250.0 843,250 [1]  
Corporacin Andina de Fomento | International funds and others [Member]          
Disclosure Of Deposits From Banks Explanatory [Line Items]          
Borrowings [2]   662,800   674,600  
Citibank N.A. [Member]          
Disclosure Of Deposits From Banks Explanatory [Line Items]          
Borrowings | $         $ 350.0
Citibank N.A. [Member] | International funds and others [Member]          
Disclosure Of Deposits From Banks Explanatory [Line Items]          
Borrowings 200.0 662,800 350.0 1,180,550  
Bank of New York Mellon [Member] | International funds and others [Member]          
Disclosure Of Deposits From Banks Explanatory [Line Items]          
Borrowings $ 100.0 331,400 [3]      
Caja Municipal de Ahorro y Crdito de Arequipa S.A. [Member] | International funds and others [Member]          
Disclosure Of Deposits From Banks Explanatory [Line Items]          
Borrowings   140,000      
Scotiabank Peru S.A.A [Member] | International funds and others [Member]          
Disclosure Of Deposits From Banks Explanatory [Line Items]          
Borrowings [4]   100,000   100,000  
Standard Chartered Bank [Member] | International funds and others [Member]          
Disclosure Of Deposits From Banks Explanatory [Line Items]          
Borrowings   86,827 $ 100.0 404,760  
Banco BBVA Per [Member] | International funds and others [Member]          
Disclosure Of Deposits From Banks Explanatory [Line Items]          
Borrowings   85,000   82,850  
Banco Consorcio [Member] | International funds and others [Member]          
Disclosure Of Deposits From Banks Explanatory [Line Items]          
Borrowings   34,627   79,526  
Deutsche Bank [Member] | International funds and others [Member]          
Disclosure Of Deposits From Banks Explanatory [Line Items]          
Borrowings   0   337,300  
Others less than S/51.0 million [Member] | International funds and others [Member]          
Disclosure Of Deposits From Banks Explanatory [Line Items]          
Borrowings   S/ 293,760   S/ 231,351  
[1] (ii)   At December 31, 2019, the balance corresponds to three variable rate loans obtained between May and November 2019 for a total of US$297.0 million, equivalent to S/984.3 million (a loan obtained in May 2018 for US$100.0 million, equivalent to S/337.3 million at December 31, 2018); the amounts of which are hedged by four IRS (an IRS at December 31, 2018) for a notional amount equal to the principal and with the same maturity, see Note 13(b). By means of the IRS, said loans were economically converted to a fixed rate.The loan that was in effect at December 31, 2018 of US$100.0 million matured during the year of 2019.(iii)  At December 31, 2019, balance comprises four variable rate loans obtained between May and July of 2019 for a total of US$190.0 million, equivalent to S/629.7 million (three loans obtained between October 2017 and October 2018 for a total amount of US$250.0 million, equivalent to S/843.3 million, at December 31, 2018), whose amounts are hedged by four IRS (three IRS at December 31, 2018) for a notional amount equal to the principal and with the same maturity, see Note 13(b). By means of these IRS, said loans were economically converted to a fixed rate.
[2] (iv)  At December 31, 2019, the balance comprises a variable rate loan in U.S. Dollars obtained in June 2019 for US$100.0 million, equivalent to S/331.4 million, the amount of which was hedged by a IRS for a notional amount equal to the principal and with the same maturity, see Note 13(b). By means of this IRS this loan was economically converted to a fixed rate.Likewise, at December 31, 2019, its included a variable rate loan in U.S. Dollars obtained in December 2017 for a total of US$100.0 million, equivalent to S/331.4 million (US$100.0 million, equivalent to S/337.3 million, at December 31, 2018) the amount of which was hedged by two CCS for a notional amount equal to the principal and with the same maturity, see Note 13(b). By means of these CCS, said loan was economically converted to a fixed rate.
[3] (vi) At December 31, 2019, the balance corresponded to a variable rate loan in U.S. Dollars obtained in August 2019 for US$100.0 million, equivalent to S/331.4
[4] (vii) At December 31, 2018, the balance included a variable rate loan obtained in October 2018 for US$100.0 million, equivalent to S/337.