2.4.0.84060 - Disclosure - SHAREHOLDERS' EQUITY (Details)truefalsefalse1false falsefalseD2012Q4_M10http://www.sec.gov/CIK0001318568duration2012-10-01T00:00:002012-10-31T00:00:002false USDfalsefalse$D2013Q2http://www.sec.gov/CIK0001318568duration2013-04-01T00:00:002013-06-30T00:00:00SharesStandardhttp://www.xbrl.org/2003/instancesharesxbrli0USDStandardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$3false falsefalseD2013Q1http://www.sec.gov/CIK0001318568duration2013-01-01T00:00:002013-03-31T00:00:004false USDfalsefalse$D2013Q2YTDhttp://www.sec.gov/CIK0001318568duration2013-01-01T00:00:002013-06-30T00:00:00SharesStandardhttp://www.xbrl.org/2003/instancesharesxbrli0USDStandardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$1true 3us-gaap_EquityClassOfTreasuryStockLineItemsus-gaap_truenadurationfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3falsefalsefalse00falsefalsefalse4falsefalsefalse00falsefalsefalsexbrli:stringItemTypestringfalse0Common Stock Repurchase Program2false 4gca_PeriodOfNewCommonStockRepurchaseProgramThatSupersedesAllExistingProgramsgca_falsenadurationfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1falsefalsefalse002 yearsfalsefalsefalse2falsefalsefalse00falsefalsefalse3falsefalsefalse00falsefalsefalse4falsefalsefalse00falsefalsefalsexbrli:durationItemTypenaRepresents the period of new common stock repurchase program that will supersedes all existing programs.No definition available.false0Period of new common stock repurchase program that will supersedes all existing programs3false 4us-gaap_StockRepurchaseProgramPeriodInForce1us-gaap_truenadurationfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3falsefalsefalse002 yearsfalsefalsefalse4falsefalsefalse00falsefalsefalsexbrli:durationItemTypenaPeriod which shares may be purchased under a stock repurchase plan authorized by an entity's Board of Directors, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.No definition available.false0Period of share repurchase under new share repurchase program4false 4us-gaap_StockRepurchasedDuringPeriodSharesus-gaap_truenadurationfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1falsefalsefalse00falsefalsefalse2truefalsefalse10000001000000falsefalsefalse3falsefalsefalse00falsefalsefalse4truefalsefalse17000001700000falsefalsefalsexbrli:sharesItemTypesharesNumber of shares that have been repurchased during the period and have not been retired and are not held in treasury. Some state laws may govern the circumstances under which an entity may acquire its own stock and prescribe the accounting treatment therefore. This element is used when state law does not recognize treasury stock.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Principles Board Opinion (APB) -Number 12 -Paragraph 10 -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 SEC -Name Regulation S-X (SX) -Number 210 -Section 04 -Article 3 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section 50 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=6928386&loc=d3e21463-112644 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Research Bulletin (ARB) -Number 43 -Section B -Paragraph 11A -Chapter 1 -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 5: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 29, 30 -Article 5 false1Shares of common stock repurchased5false 4us-gaap_StockRepurchasedDuringPeriodValueus-gaap_truedebitdurationfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1falsefalsefalse00falsefalsefalse2truefalsefalse70000007000000USD$falsetruefalse3falsefalsefalse00falsefalsefalse4truefalsefalse1170000011700000USD$falsetruefalsexbrli:monetaryItemTypemonetaryEquity impact of the value of stock that has been repurchased during the period and has not been retired and is not held in treasury. Some state laws may mandate the circumstances under which an entity may acquire its own stock and prescribe the accounting treatment therefore. This element is used when state law does not recognize treasury stock.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Principles Board Opinion (APB) -Number 12 -Paragraph 10 -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 SEC -Name Regulation S-X (SX) -Number 210 -Section 04 -Article 3 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section 50 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=6928386&loc=d3e21463-112644 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Research Bulletin (ARB) -Number 43 -Section B -Paragraph 11A -Chapter 1 -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 5: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 29, 30, 31 -Article 5 false2Aggregate purchase price of shares repurchased6true 2gca_TreasuryStockNumberOfSharesHeldRollForwardgca_falsenadurationfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3falsefalsefalse00falsefalsefalse4falsefalsefalse00falsefalsefalsexbrli:stringItemTypestringfalse0Total Number of Shares Purchased or Withheld7false 3us-gaap_RestrictedStockSharesIssuedNetOfSharesForTaxWithholdingsus-gaap_truenadurationfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1falsefalsefalse00falsefalsefalse2truefalsefalse40004000falsefalsefalse3falsefalsefalse00falsefalsefalse4truefalsefalse1100011000falsefalsefalsexbrli:sharesItemTypesharesThe number of restricted shares issued as compensation, net of shares for the payment of withholding taxes. This element is to be used only if shares are used in lieu of cash to satisfy all or a portion of withholding taxes.No definition available.false1Shares repurchased under the current plan8false 3us-gaap_RestrictedStockValueSharesIssuedNetOfTaxWithholdingsus-gaap_truecreditdurationfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1falsefalsefalse00falsefalsefalse2truefalsefalse2900029000falsefalsefalse3falsefalsefalse00falsefalsefalse4truefalsefalse7800078000falsefalsefalsexbrli:monetaryItemTypemonetaryThe value of restricted shares issued as compensation, net of the value of shares for the payment of withholding taxes. This element is to be used only if shares are used in lieu of cash to satisfy all or a portion of withholding taxes.No definition available.false2Shares withheld from restricted stock vesting (in dollars)9false 0truefalsetruefalsefalsefalsefalsefalsefalse1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3falsefalsefalse00falsefalsefalse4falsefalsefalse00falsefalsefalse5false USDtruefalse$D2013Q2YTD_MaximumMemberhttp://www.sec.gov/CIK0001318568duration2013-01-01T00:00:002013-06-30T00:00:00falsefalseMaximumus-gaap_RangeAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_MaximumMemberus-gaap_RangeAxisexplicitMemberUSDStandardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$nanafalse0Maximum10true 3us-gaap_EquityClassOfTreasuryStockLineItemsus-gaap_truenadurationfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3falsefalsefalse00falsefalsefalse4falsefalsefalse00falsefalsefalsexbrli:stringItemTypestringfalse0Common Stock Repurchase Program11false 4us-gaap_StockRepurchaseProgramAuthorizedAmountus-gaap_truecreditdurationfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3falsefalsefalse00falsefalsefalse4truefalsefalse4000000040000000USD$falsetruefalsexbrli:monetaryItemTypemonetaryThe amount authorized by an entity's Board of Directors under a stock repurchase plan.No definition available.false2Authorized repurchase amountfalseSHAREHOLDERS' EQUITY (Details) (USD $)NoRoundingNoRoundingUnKnownUnKnowntruefalsefalseSheethttp://www.gcainc.com/role/DisclosureShareholdersEquityDetails411