Document And Entity Information - USD ($)	12 Months Ended
	Dec. 31, 2020	Feb. 26, 2021	Jun. 30, 2020
Document Information [Line Items]
Entity Central Index Key	0000070487
Entity Registrant Name	National Research Corporation
Amendment Flag	false
Current Fiscal Year End Date	--12-31
Document Fiscal Period Focus	FY
Document Fiscal Year Focus	2020
Document Type	10-K
Document Annual Report	true
Document Period End Date	Dec. 31, 2020
Document Transition Report	false
Entity File Number	001-35929
Entity Incorporation, State or Country Code	WI
Entity Tax Identification Number	47-0634000
Entity Address, Address Line One	1245 Q Street
Entity Address, City or Town	Lincoln
Entity Address, State or Province	NE
Entity Address, Postal Zip Code	68508
City Area Code	402
Local Phone Number	475-2525
Title of 12(b) Security	Common Stock, $.001 par value
Trading Symbol	NRC
Security Exchange Name	NASDAQ
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Public Float			$ 653,540,609
Entity Common Stock, Shares Outstanding		25,420,408