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v2.4.1.9

Rental Activity (Details) (USD $) In Thousands, unless otherwise specified | 12 Months Ended
--- | ---
Dec. 31, 2014
Property Subject to or Available for Operating Lease [Line Items] |
2015 | 9,835us-gaap_OperatingLeasesFutureMinimumPaymentsReceivableCurrent
2016 | 1,306us-gaap_OperatingLeasesFutureMinimumPaymentsReceivableInTwoYears
Thereafter | 0ngs_OperatingLeasesFutureMinimumPaymentsReceivableAfterTwoYears
Total | 11,141us-gaap_OperatingLeasesFutureMinimumPaymentsReceivable
Minimum |
Property Subject to or Available for Operating Lease [Line Items] |
Rental arrangements, original term | 6 months
Maximum |
Property Subject to or Available for Operating Lease [Line Items] |
Rental arrangements, original term | 2 years

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- Definition Future minimum rental payments in aggregate as of the balance sheet date under operating leases. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 840 -SubTopic 20 -Section 50 -Paragraph 4 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=6454179&loc=d3e41551-112718 + Details
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- Definition Future rental payments receivable within one year of the balance sheet date under an operating lease. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 840 -SubTopic 20 -Section 50 -Paragraph 4 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=6454179&loc=d3e41551-112718 + Details
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- Definition Future rental payments receivable within the second year from the balance sheet date under an operating lease. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 840 -SubTopic 20 -Section 50 -Paragraph 4 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=6454179&loc=d3e41551-112718 + Details
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