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This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. false3Restricted stock awards, closing price11false 4us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValueus-gaap_truenadurationfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1truefalsefalse5.395.39USD$falsetruefalse2truefalsefalse5.835.83USD$falsetruefalse3truefalsefalse5.395.39USD$falsetruefalse4truefalsefalse5.835.83USD$falsetruefalsenum:perShareItemTypedecimalWeighted average fair value as of the grant date of equity-based award plans other than stock (unit) option plans that were not exercised or put into effect as a result of the occurrence of a terminating event.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (c)(2)(iii)(3) -URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901 false3Weighted Average Grant Date Fair Value, Forfeited1The exercise of SARs listed in this table resulted in the issuance of 6,999 shares of ICG’s Common Stock during the three months ended June 30, 2013.2The exercise of SARs listed in this table resulted in the issuance of 44,232 shares of ICG’s Common Stock during the six months ended June 30, 2013.falseChanges in Stock Appreciation Rights (Detail) (SARs, USD $)UnKnownNoRoundingNoRoundingUnKnowntruefalsefalseSheethttp://www.icg.com/20130630/taxonomy/role/DisclosureChangesInStockAppreciationRightsDetail411