XML 50 R23.htm IDEA: XBRL DOCUMENT v2.4.0.6

Coal and Other Mineral Rights (Tables)

3 Months Ended

Mar. 31, 2012

Coal and Other Mineral Rights [Abstract]

Coal and other mineral rights

		March 31, 2012				December 31, 2011
		(In thousands)
		(Unaudited)
Coal and other mineral rights		$	1,707,931			$	1,645,451
Less accumulated depletion and amortization			(397,341	)			(387,950	)
Net book value		$	1,310,590			$	1,257,501

		Three months ended March 31,
		2012				2011
		(In thousands)
		(Unaudited)
Total depletion and amortization expense on coal and other mineral rights		$	9,390			$	9,591

X

- Details

Name:	nrp_CoalAndOtherMineralRightsAbstract
Namespace Prefix:	nrp_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Coal and other mineral rights disclosure.

+ References

No definition available.

+ Details

Name:	nrp_CoalAndOtherMineralRightsDisclosureTableTextBlock
Namespace Prefix:	nrp_
Data Type:	nonnum:textBlockItemType
Balance Type:	na
Period Type:	duration