Name:	gbbk_FranchiseandFederalIncomeTaxWithdrawalDetailsLineItems
Namespace Prefix:	gbbk_
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Balance Type:	na
Period Type:	duration

Amount of current and deferred federal tax expense (benefit) attributable to income (loss) from continuing operations. Includes, but is not limited to, current and deferred national tax expense (benefit) for non-US (United States of America) jurisdiction.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 235
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08(h)(1)(Note 1))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480678/235-10-S99-1

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 10
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482685/740-10-50-10

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The amount of the additional liability or refund received or expected based on a final settlement with a taxing authority.

No definition available.

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

The cash outflow from advancing money to an affiliate (an entity that is related but not strictly controlled by the entity).

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 13
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482740/230-10-45-13

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Balance Type:	credit
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The cash inflow associated with the sale of investments that are pledged or subject to withdrawal restrictions during the period.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 12
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482740/230-10-45-12

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The amount of operating expenses for the period that are associated with the utility's normal revenue producing operation; including selling, general, and administrative expenses, costs incurred for routine plant repairs and maintenance, and operations.

No definition available.