Quarterly report pursuant to Section 13 or 15(d)

Business and Summary of Significant Accounting Principles (Basic EPS calculations) (Details)

v2.4.1.9
Business and Summary of Significant Accounting Principles (Basic EPS calculations) (Details) (USD $)
In Thousands, except Per Share data, unless otherwise specified
 3 Months Ended
Mar. 31, 2015
Mar. 31, 2014
Class of Stock [Line Items]    
Net income (loss) available to common stockholders $ (19,269)us-gaap_NetIncomeLossAvailableToCommonStockholdersBasic $ 1,140us-gaap_NetIncomeLossAvailableToCommonStockholdersBasic
Common Stock - Class A [Member]    
Class of Stock [Line Items]    
Net income (loss) available to common stockholders (17,723)us-gaap_NetIncomeLossAvailableToCommonStockholdersBasic
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonClassAMember 		1,052us-gaap_NetIncomeLossAvailableToCommonStockholdersBasic
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonClassAMember
Less: Undistributed income allocable to participating securities 0us-gaap_UndistributedEarningsLossAllocatedToParticipatingSecuritiesBasic
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonClassAMember 		(53)us-gaap_UndistributedEarningsLossAllocatedToParticipatingSecuritiesBasic
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonClassAMember
Undistributed income (loss) allocable to common stockholders (17,723)gncma_UndistributedIncomeLossAvailabletoCommonStockholders
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonClassAMember 		999gncma_UndistributedIncomeLossAvailabletoCommonStockholders
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonClassAMember
Weighted average common shares outstanding 36,217us-gaap_WeightedAverageNumberOfSharesOutstandingBasic
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonClassAMember 		36,081us-gaap_WeightedAverageNumberOfSharesOutstandingBasic
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonClassAMember
Basic net income (loss) attributable to GCI common stockholders per common share $ (0.49)us-gaap_EarningsPerShareBasic
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonClassAMember 		$ 0.03us-gaap_EarningsPerShareBasic
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonClassAMember
Common Stock - Class B [Member]    
Class of Stock [Line Items]    
Net income (loss) available to common stockholders (1,546)us-gaap_NetIncomeLossAvailableToCommonStockholdersBasic
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonClassBMember 		88us-gaap_NetIncomeLossAvailableToCommonStockholdersBasic
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonClassBMember
Less: Undistributed income allocable to participating securities 0us-gaap_UndistributedEarningsLossAllocatedToParticipatingSecuritiesBasic
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonClassBMember 		0us-gaap_UndistributedEarningsLossAllocatedToParticipatingSecuritiesBasic
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonClassBMember
Undistributed income (loss) allocable to common stockholders $ (1,546)gncma_UndistributedIncomeLossAvailabletoCommonStockholders
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonClassBMember 		$ 88gncma_UndistributedIncomeLossAvailabletoCommonStockholders
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonClassBMember
Weighted average common shares outstanding 3,159us-gaap_WeightedAverageNumberOfSharesOutstandingBasic
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonClassBMember 		3,163us-gaap_WeightedAverageNumberOfSharesOutstandingBasic
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonClassBMember
Basic net income (loss) attributable to GCI common stockholders per common share $ (0.49)us-gaap_EarningsPerShareBasic
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonClassBMember 		$ 0.03us-gaap_EarningsPerShareBasic
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonClassBMember