Document And Entity Information (USD $)	12 Months Ended
	Dec. 31, 2011	Jun. 30, 2011
Entity Registrant Name	NORDIC AMERICAN TANKERS Ltd
Entity Central Index Key	0001000177
Current Fiscal Year End Date	--12-31
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Filer Category	Large Accelerated Filer
Entity Public Float		$ 1,048,907,650
Entity Common Stock, Shares Outstanding	47,224,782
Document Fiscal Year Focus	2011
Document Fiscal Period Focus	FY
Document Type	20-F
Amendment Flag	false
Document Period End Date	Dec. 31, 2011