XML 32 R52.htm IDEA: XBRL DOCUMENT
v2.4.0.6

Related Party Transactions (Details 1) (USD $) In Thousands, unless otherwise specified | 3 Months Ended | 12 Months Ended
--- | --- | ---
Dec. 31, 2011 | Sep. 30, 2011 | Jun. 30, 2011 | Mar. 31, 2011 | Dec. 31, 2010 | Sep. 30, 2010 | Jun. 30, 2010 | Mar. 31, 2010 | Dec. 31, 2011 | Dec. 31, 2010 | Dec. 31, 2009
Summary of revenues from related party |  |  |  |  |  |  |  |  |  |  |
Coal royalty revenues |  |  |  |  |  |  |  |  | $ 279,221 | $ 221,761 | $ 196,621
Processing fees |  |  |  |  |  |  |  |  | 13,475 | 9,604 | 7,673
Transportation fees |  |  |  |  |  |  |  |  | 16,688 | 14,564 | 12,517
Minimums recognized as revenue |  |  |  |  |  |  |  |  | 9,148 | 14,199 | 1,266
Override revenue |  |  |  |  |  |  |  |  | 14,523 | 11,258 | 9,251
Total revenues | 90,681 | 103,164 | 96,532 | 84,852 | 77,543 | 80,752 | 79,588 | 63,519 | 377,683 | 301,401 | 256,084
Cline Affiliates [Member] |  |  |  |  |  |  |  |  |  |  |
Summary of revenues from related party |  |  |  |  |  |  |  |  |  |  |
Coal royalty revenues |  |  |  |  |  |  |  |  | 42,474 | 32,407 | 23,325
Processing fees |  |  |  |  |  |  |  |  | 2,975 | 1,337 | 193
Transportation fees |  |  |  |  |  |  |  |  | 16,689 | 14,324 | 11,495
Minimums recognized as revenue |  |  |  |  |  |  |  |  |  | 12,400 |
Override revenue |  |  |  |  |  |  |  |  | 2,691 | 1,904 | 2,356
Total revenues |  |  |  |  |  |  |  |  | $ 64,829 | $ 62,372 | $ 37,369

X
- Definition Coal processing fees. + References No definition available. + Details
Name: | nrp_CoalProcessingFees
Namespace Prefix: | nrp_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Override royalties. + References No definition available. + Details
Name: | nrp_OverrideRoyalties
Namespace Prefix: | nrp_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Details
Name: | nrp_RelatedPartyTransactionRevenuesFromTransactionsWithRelatedPartyAbstract
Namespace Prefix: | nrp_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Transportation fees. + References No definition available. + Details
Name: | nrp_TransportationFees
Namespace Prefix: | nrp_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition The amount of previously reported deferred or unearned revenue that was recognized as revenue during the period. For cash flows, this element primarily pertains to amortization of deferred credits on long-term arrangements. As a noncash item, it is deducted from net income when calculating cash provided by or used in operations using the indirect method. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Staff Accounting Bulletin (SAB) -Number Topic 13 -Section A -Subsection 1 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 28 -URI http://asc.fasb.org/extlink&oid=6943989&loc=d3e3602-108585 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 605 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SAB TOPIC 13.A.4(a).Q1) -URI http://asc.fasb.org/extlink&oid=6600647&loc=d3e214044-122780 + Details
Name: | us-gaap_RecognitionOfDeferredRevenue
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Revenue earned during the period by the entity for rights granted to another party under coal mineral leases. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 225 -SubTopic 10 -Section S99 -Paragraph 2 -Subparagraph (SX 210.5-03.1(e)) -URI http://asc.fasb.org/extlink&oid=6880815&loc=d3e20235-122688 + Details
Name: | us-gaap_RoyaltyRevenueFromCoal
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Total revenue from sale of goods and services rendered during the reporting period, in the normal course of business, reduced by sales returns and allowances, and sales discounts. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Article 5 -Section 03 -Paragraph 1 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 225 -SubTopic 10 -Section S99 -Paragraph 2 -Subparagraph (SX 210.5-03.1) -URI http://asc.fasb.org/extlink&oid=6880815&loc=d3e20235-122688 + Details
Name: | us-gaap_SalesRevenueNet
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration