RIGHT-OF-USE ASSETS AND LEASE LIABILITES (Details) - PEN (S/)
S/ in Thousands
 12 Months Ended
Dec. 31, 2019
Dec. 31, 2018
Dec. 31, 2017
Disclosure of quantitative information about right-of-use assets [line items]      
Balance at the beginning S/ 0    
Depreciation of the period 177,307 S/ 0 S/ 0
Acquisition of business and others 6,570    
Balance at the end (839,086) 0  
Net carrying amount 839,086    
Property: Agencies and offices      
Disclosure of quantitative information about right-of-use assets [line items]      
Balance at the beginning 0    
Depreciation of the period 125,462    
Acquisition of business and others 5,299    
Balance at the end   0  
Net carrying amount 688,285    
Servers and technology platforms      
Disclosure of quantitative information about right-of-use assets [line items]      
Balance at the beginning 0    
Depreciation of the period 39,891    
Acquisition of business and others 700    
Balance at the end   0  
Net carrying amount 127,780    
Spaces for ATM      
Disclosure of quantitative information about right-of-use assets [line items]      
Balance at the beginning 0    
Depreciation of the period 7,900    
Acquisition of business and others 0    
Balance at the end   0  
Net carrying amount 17,246    
Vehicles and equipment [member]      
Disclosure of quantitative information about right-of-use assets [line items]      
Balance at the beginning 0    
Depreciation of the period 400    
Acquisition of business and others 571    
Balance at the end   0  
Net carrying amount 2,035    
Other leases      
Disclosure of quantitative information about right-of-use assets [line items]      
Balance at the beginning 0    
Depreciation of the period 3,654    
Acquisition of business and others 0    
Balance at the end   S/ 0  
Net carrying amount 3,740    
Cost      
Disclosure of quantitative information about right-of-use assets [line items]      
Balance at the end (1,022,963)    
Cost | Property: Agencies and offices      
Disclosure of quantitative information about right-of-use assets [line items]      
Balance at the end (819,046)    
Cost | Servers and technology platforms      
Disclosure of quantitative information about right-of-use assets [line items]      
Balance at the end (168,371)    
Cost | Spaces for ATM      
Disclosure of quantitative information about right-of-use assets [line items]      
Balance at the end (25,146)    
Cost | Vehicles and equipment [member]      
Disclosure of quantitative information about right-of-use assets [line items]      
Balance at the end (3,006)    
Cost | Other leases      
Disclosure of quantitative information about right-of-use assets [line items]      
Balance at the end (7,394)    
Accumulated depreciation      
Disclosure of quantitative information about right-of-use assets [line items]      
Balance at the end 183,877    
Accumulated depreciation | Property: Agencies and offices      
Disclosure of quantitative information about right-of-use assets [line items]      
Balance at the end 130,761    
Accumulated depreciation | Servers and technology platforms      
Disclosure of quantitative information about right-of-use assets [line items]      
Balance at the end 40,591    
Accumulated depreciation | Spaces for ATM      
Disclosure of quantitative information about right-of-use assets [line items]      
Balance at the end 7,900    
Accumulated depreciation | Vehicles and equipment [member]      
Disclosure of quantitative information about right-of-use assets [line items]      
Balance at the end 971    
Accumulated depreciation | Other leases      
Disclosure of quantitative information about right-of-use assets [line items]      
Balance at the end S/ 3,654