XML 33 R32.htm IDEA: XBRL DOCUMENT
v2.4.1.9

Other Long-term Liabilities (Details) (USD $) | 3 Months Ended | 0 Months Ended |  |  |
--- | --- | --- | --- | --- | ---
Mar. 31, 2013 | Jul. 30, 2008 | Dec. 31, 2012 | Dec. 31, 2014 | Dec. 31, 2013
Other Long-term Liabilities |  |  |  |  |
Deferred revenue, noncurrent, related to certain staffing requirements |  |  | $ 275,000us-gaap_DeferredRevenueNoncurrent |  |
Payments to settle deferred revenue liability | 52,000ngs_PaymentsToSettleDeferredRevenueLiability |  |  |  |
Gain (loss) on settlement of deferred revenue liability | 223,000ngs_GainLossOnSettlementOfDeferredRevenueLiability |  |  |  |
Paint and Coatings |  |  |  |  |
Other Long-term Liabilities |  |  |  |  |
Long-term purchase commitment, amount |  | 4,800,000us-gaap_LongTermPurchaseCommitmentAmount / us-gaap_LongTermPurchaseCommitmentByCategoryOfItemPurchasedAxis = us-gaap_InventoriesMember |  |  |
Cash received from supplier as discount toward future purchases |  | 300,000ngs_LongTermPurchaseCommitmentCashReceivedAsDiscountTowardFuturePurchases / us-gaap_LongTermPurchaseCommitmentByCategoryOfItemPurchasedAxis = us-gaap_InventoriesMember |  |  |
Liability related to deferred discount |  | $ 300,000ngs_LongTermPurchaseCommitmentLiabilityRelatedToDeferredDiscount / us-gaap_LongTermPurchaseCommitmentByCategoryOfItemPurchasedAxis = us-gaap_InventoriesMember |  | $ 155,000ngs_LongTermPurchaseCommitmentLiabilityRelatedToDeferredDiscount / us-gaap_LongTermPurchaseCommitmentByCategoryOfItemPurchasedAxis = us-gaap_InventoriesMember | $ 197,000ngs_LongTermPurchaseCommitmentLiabilityRelatedToDeferredDiscount / us-gaap_LongTermPurchaseCommitmentByCategoryOfItemPurchasedAxis = us-gaap_InventoriesMember

X
- Definition Gain (Loss) on Settlement of Deferred Revenue Liability + References No definition available. + Details
Name: | ngs_GainLossOnSettlementOfDeferredRevenueLiability
Namespace Prefix: | ngs_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Long-term Purchase Commitment, Cash Received as Discount toward Future Purchases + References No definition available. + Details
Name: | ngs_LongTermPurchaseCommitmentCashReceivedAsDiscountTowardFuturePurchases
Namespace Prefix: | ngs_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Long-term Purchase Commitment, Liability Related to Deferred Discount + References No definition available. + Details
Name: | ngs_LongTermPurchaseCommitmentLiabilityRelatedToDeferredDiscount
Namespace Prefix: | ngs_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

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

X
- Definition Payments to Settle Deferred Revenue Liability + References No definition available. + Details
Name: | ngs_PaymentsToSettleDeferredRevenueLiability
Namespace Prefix: | ngs_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition The noncurrent portion of deferred revenue amount as of balance sheet date. Deferred revenue is a liability related to a revenue producing activity for which revenue has not yet been recognized, and is not expected to be recognized in the next twelve months. Generally, an entity records deferred revenue when it receives consideration from a customer before achieving certain criteria that must be met for revenue to be recognized in conformity with GAAP. + References Reference 1: 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=27012821&loc=d3e214044-122780 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section 45 -Paragraph 8 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=28358313&loc=d3e6935-107765 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Staff Accounting Bulletin (SAB) -Number Topic 13 -Section A + Details
Name: | us-gaap_DeferredRevenueNoncurrent
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition The minimum amount the entity agreed to spend under the long-term purchase commitment. + References No definition available. + Details
Name: | us-gaap_LongTermPurchaseCommitmentAmount
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Details
Name: | us-gaap_LongTermPurchaseCommitmentByCategoryOfItemPurchasedAxis=us-gaap_InventoriesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |