RESULTS FOR THE YEAR - INCOME TAXES AND DEFERRED INCOME TAXES - Narrative (Details) - DKK DKK in Millions	12 Months Ended
Dec. 31, 2017	Dec. 31, 2016
Analysis of income and expense [abstract]
Increase (decrease) in current tax expense (income) due to rate regulation	DKK 171
Potential withholding tax amounts related to distribution of earnings	DKK 343	DKK 330

The increase (decrease) in current tax expense (income) due to rate regulation. Rate regulation is a framework for establishing the prices that can be charged to customers for goods or services and that framework is subject to oversight and/or approval by a rate regulator. [Refer: Current tax expense (income)]

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 14
-IssueDate 2017-01-01
-Paragraph 34
-URI http://eifrs.ifrs.org/eifrs/XBRL?type=IFRS&num=14&date=2017-03-01&anchor=para_34&doctype=Standard
-URIDate 2017-03-09

Name:	ifrs-full_IncreaseDecreaseInCurrentTaxExpenseIncomeDueToRateRegulation
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration