Statement Of Comprehensive Income [Abstract]

NATIONWIDE BUILDING SOCIETY - Filing #4370996

Concept	2023-04-05 to 2024-04-04	2023-04-05 to 2024-04-04	2023-04-05 to 2024-04-04	2023-04-05 to 2024-04-04	2023-04-05 to 2024-04-04	2023-04-05 to 2024-04-04	2023-04-05 to 2024-04-04	2023-04-05 to 2024-04-04	2022-04-05 to 2023-04-04	2022-04-05 to 2023-04-04	2022-04-05 to 2023-04-04	2022-04-05 to 2023-04-04	2022-04-05 to 2023-04-04	2022-04-05 to 2023-04-04	2022-04-05 to 2023-04-04	2022-04-05 to 2023-04-04
Statement of comprehensive income [abstract]
Profit (loss)	- GBP	1,300,000,000 GBP	- GBP	- GBP	- GBP	- GBP	- GBP	1,300,000,000 GBP	1,664,000,000 GBP	- GBP	- GBP	- GBP	1,664,000,000 GBP	- GBP	- GBP	- GBP
Other comprehensive income [abstract]
Components of other comprehensive income that will not be reclassified to profit or loss, net of tax [abstract]
Other comprehensive income, net of tax, gains (losses) from investments in equity instruments	—	4,000,000 GBP	—	—	—	—	—	—	—	—	—	—	2,000,000 GBP	—	—	—
Other comprehensive income, net of tax, gains (losses) on revaluation of property, plant and equipment, right-of-use assets and intangible assets	2,000,000 GBP	2,000,000 GBP	- GBP	- GBP	- GBP	- GBP	- GBP	- GBP	- GBP	1,000,000 GBP	- GBP	- GBP	1,000,000 GBP	- GBP	- GBP	- GBP
Other comprehensive income, net of tax, gains (losses) on remeasurements of defined benefit plans	- GBP	190,000,000 GBP	- GBP	- GBP	- GBP	- GBP	- GBP	190,000,000 GBP	56,000,000 GBP	- GBP	- GBP	- GBP	56,000,000 GBP	- GBP	- GBP	- GBP
Other comprehensive income that will not be reclassified to profit or loss, net of tax	—	188,000,000 GBP	—	—	—	—	—	—	—	—	—	—	57,000,000 GBP	—	—	—
Components of other comprehensive income that will be reclassified to profit or loss, net of tax [abstract]
Cash flow hedges [abstract]
Other comprehensive income, net of tax, cash flow hedges	- GBP	49,000,000 GBP	49,000,000 GBP	- GBP	- GBP	- GBP	- GBP	- GBP	- GBP	- GBP	8,000,000 GBP	- GBP	8,000,000 GBP	- GBP	- GBP	- GBP
Cost of hedging [abstract]
Change in value of foreign currency basis spreads [abstract]
Other comprehensive income, net of tax, change in value of foreign currency basis spreads	- GBP	4,000,000 GBP	- GBP	- GBP	- GBP	4,000,000 GBP	- GBP	- GBP	- GBP	- GBP	- GBP	- GBP	4,000,000 GBP	- GBP	4,000,000 GBP	- GBP
Financial assets measured at fair value through other comprehensive income [abstract]
Other comprehensive income, net of tax, financial assets measured at fair value through other comprehensive income	—	28,000,000 GBP	—	—	—	—	—	—	—	—	—	—	101,000,000 GBP	—	—	—
Other comprehensive income that will be reclassified to profit or loss, net of tax	—	81,000,000 GBP	—	—	—	—	—	—	—	—	—	—	113,000,000 GBP	—	—	—
Other comprehensive income	—	269,000,000 GBP	—	—	—	—	—	—	—	—	—	—	170,000,000 GBP	—	—	—
Comprehensive income	2,000,000 GBP	1,031,000,000 GBP	49,000,000 GBP	- GBP	- GBP	4,000,000 GBP	24,000,000 GBP	1,110,000,000 GBP	1,608,000,000 GBP	1,000,000 GBP	8,000,000 GBP	- GBP	1,494,000,000 GBP	- GBP	4,000,000 GBP	103,000,000 GBP