Capital structure and financial items - Cash and cash equivalents, financial resources and free cash flow- Narrative (Details) - DKK (kr) kr in Millions	Dec. 31, 2019	Dec. 31, 2018
Share Capital, Reserves And Other Equity Interest And Financial Instruments [Abstract]
Restricted cash and cash equivalents	kr 509	kr 120

The amount of cash and cash equivalents whose use or withdrawal is restricted. [Refer: Cash and cash equivalents]

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Name IAS
-Number 1
-IssueDate 2019-01-01
-Paragraph 55
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=1&code=ifrs-tx-2019-en-r&anchor=para_55&doctype=Standard
-URIDate 2019-03-27

Name:	ifrs-full_RestrictedCashAndCashEquivalents
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant