Cover Page - USD ($)	12 Months Ended
	Dec. 31, 2021	Mar. 07, 2022	Jun. 30, 2021
Entity Information [Line Items]
Document Type	10-K
Document Annual Report	true
Document Period End Date	Dec. 31, 2021
Current Fiscal Year End Date	--12-31
Document Transition Report	false
Entity File Number	000-55522
Entity Registrant Name	NATIONAL WESTERN LIFE GROUP, INC.
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	47-3339380
Entity Address, Address Line One	10801 N. Mopac Expy Bldg 3
Entity Address, City or Town	Austin,
Entity Address, State or Province	TX
Entity Address, Postal Zip Code	78759
City Area Code	(512)
Local Phone Number	836-1010
Title of 12(b) Security	Class A Common Stock, $0.01 par value
Trading Symbol	NWLI
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
ICFR Auditor Attestation Flag	true
Entity Shell Company	false
Entity Public Float			$ 574,415,512
Documents Incorporated by Reference	Documents incorporated by reference:  Portions of the registrant’s definitive proxy statement for the annual meeting of shareholders to be held June 17, 2022, which will be filed within 120 days after December 31, 2021, are incorporated by reference into Part III of this report.
Entity Central Index Key	0001635984
Document Fiscal Year Focus	2021
Document Fiscal Period Focus	FY
Amendment Flag	false
Class A
Entity Information [Line Items]
Entity Common Stock, Shares Outstanding		3,436,020
Class B
Entity Information [Line Items]
Entity Common Stock, Shares Outstanding		200,000