Statement Of Changes In Equity [Abstract]

Novonesis AS - Filing #1443478

Concept	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	2019-01-01 to 2019-12-31	2019-01-01 to 2019-12-31	2019-01-01 to 2019-12-31	2019-01-01 to 2019-12-31
Statement of changes in equity [abstract]
Statement of changes in equity [line items]
Decrease (increase) through tax on share-based payment transactions, equity	37,000,000 DKK	—	37,000,000 DKK	37,000,000 DKK	—	19,000,000 DKK	19,000,000 DKK	19,000,000 DKK
Purchase of treasury shares	1,500,000,000 DKK	—	1,500,000,000 DKK	1,500,000,000 DKK	—	2,000,000,000 DKK	2,000,000,000 DKK	2,000,000,000 DKK
Sale or issue of treasury shares	508,000,000 DKK	—	508,000,000 DKK	508,000,000 DKK	—	75,000,000 DKK	75,000,000 DKK	75,000,000 DKK
Reduction of issued capital	12,000,000 DKK	12,000,000 DKK	- DKK	- DKK	12,000,000 DKK	- DKK	12,000,000 DKK	- DKK