Receivables from and Payables to Brokers, Dealers, and Clearing Organizations (Details) (USD $)	Jun. 30, 2012	Dec. 31, 2011
Receivables from and Payables to Brokers, Dealers, and Clearing Organizations
Deposits with clearing organizations	$ 19,182,000	$ 16,467,000
Receivable for unsettled trading activities	7,203,000	14,705,000
Receivable from clearing organizations	5,043,000	2,950,000
Fails to deliver	5,000	24,654,000
Underwriting and syndicate fees receivable	149,000
Total receivables	31,582,000	58,776,000
Payable to clearing organizations	500,882,000	1,093,518,000
Fails to receive		15,146,000
Total payables	500,882,000	1,108,664,000
Deposit with FICC	$ 18,400,000	$ 15,200,000

Represents the amount of securities on deposit with the Fixed Income Clearing Corporation.

No definition available.

Name:	glch_DepositsWithFixedIncomeClearingCorporation
Namespace Prefix:	glch_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Represents the amount payable to clearing organizations.

+ References

No definition available.

+ Details

Name:	glch_PayableToClearingOrganizations
Namespace Prefix:	glch_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Represents the amount of receivable for unsettled trading activities.

+ References

No definition available.

+ Details

Name:	glch_ReceivableForUnsettledTradingActivities
Namespace Prefix:	glch_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Details

Name:	glch_ReceivablesFromAndPayablesToBrokersDealersAndClearingAgenciesDisclosureAbstract
Namespace Prefix:	glch_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Represents the amount of underwriting and syndicate fees receivable.

+ References

No definition available.

+ Details

Name:	glch_UnderwritingAndSyndicateFeesReceivable
Namespace Prefix:	glch_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

The amount of securities on deposit with clearing organizations and other entities which provide services necessary to operations of the Company. This item would include, for instance, securities advanced as refundable collateral for securities borrowed.

+ 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 210.5-02.8,17)

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

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

-Publisher AICPA

-Name Audit and Accounting Guide (AAG)

-Number AAG-BRD

-Paragraph 31

-IssueDate 2006-05-01

-Chapter 4

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

+ Details

Name:	us-gaap_DepositsWithClearingOrganizationsAndOthersSecurities
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Aggregate amounts payable to broker-dealers and clearing organizations include amounts payable for securities failed to receive, certain deposits received for securities loaned, amounts payable to clearing organizations on open transactions, and floor-brokerage payables. In addition, the net receivable or payable arising from unsettled trades would be reflected in those captions. A broker-dealer that purchases securities, either for its own account or for a customer's account, but does not receive the securities on the settlement date records the amount of money representing the purchase price of the securities, including any accrued interest, as a liability to the selling broker-dealer. This liability is paid when the securities are received by the purchasing broker-dealer.

+ References

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

-Publisher AICPA

-Name Audit and Accounting Guide (AAG)

-Number AAG-BRD

-Paragraph 80

-Subparagraph Exhibit 4-8, 4

-IssueDate 2006-05-01

-Chapter 4

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

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

-Publisher AICPA

-Name Audit and Accounting Guide (AAG)

-Number AAG-BRD

-Paragraph 24, 25

-IssueDate 2006-05-01

-Chapter 7

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher AICPA

-Name Audit and Accounting Guide (AAG)

-Number AAG-BRD

-Paragraph 24-31, 35

-IssueDate 2006-05-01

-Chapter 4

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

+ Details

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

- Definition

Amount receivable from securities failed to deliver, certain deposits for securities borrowed, open transactions, good faith and margin deposits, commissions and floor brokerage items. Also cash and securities [guarantee] on deposit with [commodities] clearing organizations and other entities which provide services necessary to operations of the Company. This item would include, for instance, cash and securities advanced as [refundable] collateral for securities borrowed.

+ References

+ Details

Name:	us-gaap_ReceivablesFromBrokersDealersAndClearingOrganizations
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Cash and securities on deposit with the expectation that such deposits will be returned with organizations that provide efficient and orderly trade clearance and settlement services for which broker-dealers pay fees. Clearing organizations perform post trade processing and trade comparisons among numerous broker-dealers and act as settlement agents between buying and selling broker-dealers.

+ References

+ Details

Name:	us-gaap_ReceivablesFromClearingOrganizations
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Amount recorded when a Broker Dealer sells securities but does not deliver the securities on settlement date. The amount recorded is the selling price including any accrued interest. This asset is collected upon delivery of the securities.

+ References

+ Details

Name:	us-gaap_SecuritiesFailedToDeliver
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

A broker-dealer that purchases securities but does not receive the securities by the agreed settlement date records the price of the securities and any accrued interest as a liability called Securities Failed-to-Receive to the selling broker. The liability is paid when the securities are received by the purchasing broker dealer.

+ References

+ Details

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