Statement Of Comprehensive Income [Abstract]

NATIONWIDE BUILDING SOCIETY - Filing #4413769

Concept	2021-04-05 to 2022-04-04	2021-04-05 to 2022-04-04	2021-04-05 to 2022-04-04	2021-04-05 to 2022-04-04	2021-04-05 to 2022-04-04	2021-04-05 to 2022-04-04	2021-04-05 to 2022-04-04	2021-04-05 to 2022-04-04	2020-04-05 to 2021-04-04	2020-04-05 to 2021-04-04	2020-04-05 to 2021-04-04	2020-04-05 to 2021-04-04	2020-04-05 to 2021-04-04	2020-04-05 to 2021-04-04	2020-04-05 to 2021-04-04	2020-04-05 to 2021-04-04
Statement of comprehensive income [abstract]
Profit (loss)	1,252,000,000 GBP	- GBP	- GBP	- GBP	- GBP	1,252,000,000 GBP	- GBP	- GBP	- GBP	618,000,000 GBP	- GBP	- GBP	- GBP	618,000,000 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	—	—	—	—	—	8,000,000 GBP	—	—	—	3,000,000 GBP	—	—	—	—	—	—
Other comprehensive income, net of tax, gains (losses) on revaluation of property, plant and equipment, right-of-use assets and intangible assets	- GBP	5,000,000 GBP	- GBP	- GBP	- GBP	5,000,000 GBP	- GBP	- GBP	- GBP	2,000,000 GBP	- GBP	- GBP	- GBP	- GBP	2,000,000 GBP	- GBP
Other comprehensive income, net of tax, gains (losses) on remeasurements of defined benefit plans	543,000,000 GBP	- GBP	- GBP	- GBP	- GBP	543,000,000 GBP	- GBP	- GBP	- GBP	72,000,000 GBP	- GBP	- GBP	- GBP	72,000,000 GBP	- GBP	- GBP
Other comprehensive income that will not be reclassified to profit or loss, net of tax	—	—	—	—	—	556,000,000 GBP	—	—	—	67,000,000 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	- GBP	11,000,000 GBP	- GBP	- GBP	11,000,000 GBP	- GBP	- GBP	- GBP	111,000,000 GBP	- GBP	- GBP	111,000,000 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	- GBP	- GBP	- GBP	- GBP	3,000,000 GBP	3,000,000 GBP	- GBP	- GBP	4,000,000 GBP	4,000,000 GBP	- GBP	- GBP	- GBP	- 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	—	—	—	128,000,000 GBP	—	—	—	—	—	—
Other comprehensive income	—	—	—	—	—	520,000,000 GBP	—	—	—	54,000,000 GBP	—	—	—	—	—	—
Comprehensive income	1,795,000,000 GBP	5,000,000 GBP	11,000,000 GBP	- GBP	- GBP	1,772,000,000 GBP	3,000,000 GBP	20,000,000 GBP	- GBP	564,000,000 GBP	4,000,000 GBP	131,000,000 GBP	111,000,000 GBP	546,000,000 GBP	2,000,000 GBP	- GBP