Note 8 - Financing Arrangements and Fair Value of Financial Instruments (Details) (USD $)	3 Months Ended
Mar. 31, 2014	Dec. 31, 2013
Senior Notes [Member]
Note 8 - Financing Arrangements and Fair Value of Financial Instruments (Details) [Line Items]
Debt Instrument, Face Amount	$ 172,500,000
Debt Instrument, Interest Rate, Stated Percentage	4.00%
Debt Conversion Converted Instrument Shares Issued For Basis Principal (in Shares)	90.8893
Debt Conversion Principal Amount Of Senior Notes As Basis For Conversion Rate	1,000
Debt Instrument, Convertible, Conversion Price (in Dollars per share)	$ 11.00
Fair Value, Estimate Not Practicable, Senior Debt Obligations	219,100,000	231,200,000
Revolving Credit Facility [Member]
Note 8 - Financing Arrangements and Fair Value of Financial Instruments (Details) [Line Items]
Additional Borrowing Capacity on Credit Facility	75,000,000
Minimum [Member] \| Revolving Credit Facility [Member]
Note 8 - Financing Arrangements and Fair Value of Financial Instruments (Details) [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity	125,000,000
Maximum [Member] \| Revolving Credit Facility [Member]
Note 8 - Financing Arrangements and Fair Value of Financial Instruments (Details) [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity	$ 200,000,000

Additional Borrowing Capacity on Credit Facility.

No definition available.

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Namespace Prefix:	nr_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Debt conversion converted instrument shares issued for basis principal.

+ References

No definition available.

+ Details

Name:	nr_DebtConversionConvertedInstrumentSharesIssuedForBasisPrincipal
Namespace Prefix:	nr_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

- Definition

Debt conversion principal amount of senior notes as basis for conversion rate.

+ References

No definition available.

+ Details

Name:	nr_DebtConversionPrincipalAmountOfSeniorNotesAsBasisForConversionRate
Namespace Prefix:	nr_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Details

Name:	nr_Note8FinancingArrangementsandFairValueofFinancialInstrumentsDetailsLineItems
Namespace Prefix:	nr_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

The price per share of the conversion feature embedded in the debt instrument.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 470

-SubTopic 20

-Section 50

-Paragraph 5

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=6928298&loc=SL6031898-161870

+ Details

Name:	us-gaap_DebtInstrumentConvertibleConversionPrice1
Namespace Prefix:	us-gaap_
Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	instant

- Definition

Face (par) amount of debt instrument at time of issuance.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 835

-SubTopic 30

-Section 45

-Paragraph 2

-URI http://asc.fasb.org/extlink&oid=6451184&loc=d3e28551-108399

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 835

-SubTopic 30

-Section 55

-Paragraph 8

-URI http://asc.fasb.org/extlink&oid=6584090&loc=d3e28878-108400

+ Details

Name:	us-gaap_DebtInstrumentFaceAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Contractual interest rate for funds borrowed, under the debt agreement.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 22

-Article 5

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.22(a)(1))

-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

+ Details

Name:	us-gaap_DebtInstrumentInterestRateStatedPercentage
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

This item represents a financial instrument (as defined) for which it is not practicable to estimate fair value. Such disclosure may be for an individual financial instrument or a class of financial instruments.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 825

-SubTopic 10

-Section 50

-Paragraph 16

-URI http://asc.fasb.org/extlink&oid=28364263&loc=d3e13504-108611

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.19(b),22(b))

-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 19, 22

-Article 5

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant