Statement Of Changes In Equity [Abstract]

Severn Trent PLC - Filing #1737782

Concept	2021-04-01 to 2022-03-31	2021-04-01 to 2022-03-31	2021-04-01 to 2022-03-31	2021-04-01 to 2022-03-31	2021-04-01 to 2022-03-31	2021-04-01 to 2022-03-31	As at 2022-03-31	As at 2022-03-31	As at 2022-03-31	2021-04-01 to 2022-03-31	As at 2022-03-31	As at 2022-03-31	2020-04-01 to 2021-03-31	2020-04-01 to 2021-03-31	As at 2021-03-31	As at 2021-03-31	As at 2021-03-31	As at 2021-03-31	As at 2021-03-31	2020-04-01 to 2021-03-31	2020-04-01 to 2021-03-31	2020-04-01 to 2021-03-31	2020-04-01 to 2021-03-31	2020-04-01 to 2021-03-31	As at 2020-03-31	As at 2020-03-31	As at 2020-03-31	As at 2020-03-31	As at 2020-03-31
Statement of changes in equity [abstract]
Statement of changes in equity [line items]
Equity	—	—	—	—	—	—	248,100,000 GBP	394,400,000 GBP	473,000,000 GBP	—	1,263,900,000 GBP	148,400,000 GBP	—	—	651,700,000 GBP	1,138,700,000 GBP	237,200,000 GBP	148,100,000 GBP	101,700,000 GBP	—	—	—	—	—	67,900,000 GBP	1,243,700,000 GBP	137,000,000 GBP	236,500,000 GBP	802,300,000 GBP
Changes in equity [abstract]
Comprehensive income [abstract]
Profit (loss)	– GBP	87,200,000 GBP	296,500,000 GBP	209,300,000 GBP	– GBP	– GBP	—	—	—	87,200,000 GBP	—	—	219,200,000 GBP	7,000,000 GBP	—	—	—	—	—	– GBP	212,200,000 GBP	– GBP	– GBP	212,200,000 GBP	—	—	—	—	—
Other comprehensive income	—	—	—	—	—	—	—	—	—	196,500,000 GBP	—	—	—	—	—	—	—	—	—	—	97,400,000 GBP	—	—	—	—	—	—	—	—
Comprehensive income	– GBP	62,600,000 GBP	—	—	46,700,000 GBP	– GBP	—	—	—	109,300,000 GBP	—	—	—	—	—	—	—	—	—	33,800,000 GBP	114,800,000 GBP	– GBP	– GBP	81,000,000 GBP	—	—	—	—	—
Dividends recognised as distributions to owners	– GBP	254,500,000 GBP	—	—	– GBP	– GBP	—	—	—	254,500,000 GBP	—	—	—	—	—	—	—	—	—	– GBP	240,200,000 GBP	– GBP	– GBP	240,200,000 GBP	—	—	—	—	—