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Revenue and Contract Costs - Pass Through Costs (Details) | 3 Months Ended | 6 Months Ended
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Jun. 30, 2017 | Jun. 30, 2016 | Jun. 30, 2017 | Jun. 30, 2016
Contractors [Abstract] |  |  |  |
Pass-through costs as a percentage of revenues | 53.10% | 35.10% | 41.90% | 37.60%

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- Definition Pass through costs as percent of revenue + References No definition available. + Details
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Namespace Prefix: | gifi_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

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- References No definition available. + Details
Name: | us-gaap_ContractorsAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration