Limits On Common Stock Ownership Limits On Common Stock Ownership (Narrative) (Details)	12 Months Ended
Dec. 31, 2018
Limits On Common Stock Ownership [Abstract]
Maximum Number of Equity Owners, Closely Held Designation	100
Common Stock Ownership Limit	9.90%
Excepted Holder Agreement, Common Stock, Ownership Limit	7.50%

This item represents the maximum amount of the Company's common stock any individual shareholder is allowed to own as a result of the Excepted Holder Agreements which became effective May 12, 2008 represented as a percentage of the total number of shares outstanding as provided by certain provisions of the Company's charter.

No definition available.

Name:	nhi_ExceptedHolderAgreementCommonStockOwnershipLimit
Namespace Prefix:	nhi_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration