Statement Of Comprehensive Income [Abstract]

Direct Line Insurance Group PLC - Filing #2024748

Concept	2023-01-01 to 2023-12-31	2022-01-01 to 2023-12-31	2022-01-01 to 2023-12-31	2022-01-01 to 2023-12-31	2022-01-01 to 2023-12-31	2022-01-01 to 2023-12-31	2022-01-01 to 2023-12-31	2022-01-01 to 2023-12-31	2022-01-01 to 2023-12-31	2022-01-01 to 2023-12-31	2022-01-01 to 2023-12-31	2022-01-01 to 2022-12-31	2022-01-01 to 2022-12-31	2022-01-01 to 2022-12-31	2022-01-01 to 2022-12-31	2022-01-01 to 2022-12-31	2022-01-01 to 2022-12-31	2022-01-01 to 2022-12-31	2022-01-01 to 2022-12-31	2022-01-01 to 2022-12-31	2022-01-01 to 2022-12-31
Statement of comprehensive income [abstract]
Profit (loss)	—	— GBP	222,900,000 GBP	222,900,000 GBP	— GBP	— GBP	— GBP	— GBP	— GBP	— GBP	222,900,000 GBP	— GBP	— GBP	231,900,000 GBP	231,900,000 GBP	— GBP	— GBP	— GBP	— GBP	231,900,000 GBP	— GBP
Other comprehensive income [abstract]
Components of other comprehensive income that will not be reclassified to profit or loss, before tax [abstract]
Other comprehensive income, before tax, gains (losses) from investments in equity instruments	3,300,000 GBP	—	—	—	—	—	—	—	—	—	—	—	—	600,000 GBP	—	—	—	—	—	—	—
Other comprehensive income, before tax, gains (losses) on remeasurements of defined benefit plans	100,000 GBP	—	—	—	—	—	—	—	—	—	—	—	—	9,800,000 GBP	—	—	—	—	—	—	—
Other comprehensive income, before tax, change in fair value of financial liability attributable to change in credit risk of liability	600,000 GBP	—	—	—	—	—	—	—	—	—	—	—	—	— GBP	—	—	—	—	—	—	—
Components of other comprehensive income that will be reclassified to profit or loss, before tax [abstract]
Cash flow hedges [abstract]
Gains (losses) on cash flow hedges, before tax	200,000 GBP	—	—	—	—	—	—	—	—	—	—	—	—	300,000 GBP	—	—	—	—	—	—	—
Income tax relating to components of other comprehensive income that will not be reclassified to profit or loss [abstract]
Income tax relating to remeasurements of defined benefit plans included in other comprehensive income	— GBP	—	—	—	—	—	—	—	—	—	—	—	—	2,500,000 GBP	—	—	—	—	—	—	—
Other comprehensive income	2,600,000 GBP	— GBP	100,000 GBP	2,600,000 GBP	— GBP	200,000 GBP	2,700,000 GBP	— GBP	— GBP	— GBP	2,600,000 GBP	— GBP	— GBP	7,600,000 GBP	7,300,000 GBP	— GBP	— GBP	— GBP	600,000 GBP	7,600,000 GBP	300,000 GBP
Comprehensive income	—	— GBP	223,000,000 GBP	225,500,000 GBP	— GBP	200,000 GBP	2,700,000 GBP	— GBP	— GBP	— GBP	225,500,000 GBP	— GBP	— GBP	239,500,000 GBP	239,200,000 GBP	— GBP	— GBP	— GBP	600,000 GBP	239,500,000 GBP	300,000 GBP
Comprehensive income attributable to [abstract]
Comprehensive income, attributable to owners of parent	225,500,000 GBP	—	—	—	—	—	—	—	—	—	—	—	—	239,500,000 GBP	—	—	—	—	—	—	—