Statement Of Changes In Equity [Abstract]

Direct Line Insurance Group PLC - Filing #3490597

Concept	2021-01-01 to 2021-12-31	2021-01-01 to 2021-12-31	2021-01-01 to 2021-12-31	2021-01-01 to 2021-12-31	2021-01-01 to 2021-12-31	2021-01-01 to 2021-12-31	2021-01-01 to 2021-12-31	2021-01-01 to 2021-12-31	2021-01-01 to 2021-12-31	2020-01-01 to 2020-12-31	2020-01-01 to 2020-12-31	2020-01-01 to 2020-12-31	2020-01-01 to 2020-12-31	2020-01-01 to 2020-12-31	2020-01-01 to 2020-12-31	2020-01-01 to 2020-12-31	2020-01-01 to 2020-12-31	2020-01-01 to 2020-12-31
Statement of changes in equity [abstract]
Statement of changes in equity [line items]
Decrease (increase) through tax on share-based payment transactions, equity	— GBP	— GBP	— GBP	— GBP	— GBP	700,000 GBP	— GBP	700,000 GBP	700,000 GBP	500,000 GBP	— GBP	— GBP	500,000 GBP	— GBP	— GBP	500,000 GBP	— GBP	— GBP
Increase (decrease) through transactions with owners, equity	— GBP	3,700,000 GBP	1,100,000 GBP	3,700,000 GBP	— GBP	421,000,000 GBP	— GBP	421,000,000 GBP	419,900,000 GBP	337,200,000 GBP	— GBP	1,100,000 GBP	347,300,000 GBP	— GBP	— GBP	347,300,000 GBP	1,100,000 GBP	10,100,000 GBP
Cancellation of treasury shares	— GBP	3,700,000 GBP	— GBP	3,700,000 GBP	— GBP	101,000,000 GBP	— GBP	101,000,000 GBP	101,000,000 GBP	30,000,000 GBP	— GBP	1,100,000 GBP	30,000,000 GBP	— GBP	— GBP	30,000,000 GBP	1,100,000 GBP	— GBP