Note 21 - Property and Equipment (Detail: Text Values) - EUR (€) € in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Property and Equipment [Line Items]
Carrying value of items of property and equipment on which there is a restriction on sale	€ 24	€ 25
Commitments for the acquisition of property and equipment	96	150
Additions to Right-of-use assets (IFRS 16), mainly new real estate leases	263
Depreciation charges for Right-of-use assets (IFRS 16), mainly resulted from planned consumption for property leases	543
Carrying amount of right-of-use assets	4,000	4,000
of which: Real estate leases	4,000	4,000
Of which: Vehicle leases	€ 13	€ 10