Quarterly report pursuant to Section 13 or 15(d)

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

v2.4.1.9
Business and Summary of Significant Accounting Principles (Diluted EPS calculations) (Details) (USD $)
In Thousands, except Per Share data, unless otherwise specified
3 Months Ended
Mar. 31, 2015
Mar. 31, 2014
Common Stock - Class A [Member]    
Class of Stock [Line Items]    
Allocation of undistributed earnings (loss) for basic computation $ (17,723)gncma_UndistributedIncomeLossAvailabletoCommonStockholders
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonClassAMember
$ 999gncma_UndistributedIncomeLossAvailabletoCommonStockholders
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonClassAMember
Reallocation of undistributed earnings (loss) as a result of conversion of Class B to Class A shares (1,546)gncma_DilutiveSecuritiesEffectOnBasicEarningsPerShareConversionofCommonStock
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonClassAMember
88gncma_DilutiveSecuritiesEffectOnBasicEarningsPerShareConversionofCommonStock
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonClassAMember
Net income (loss) adjusted for allocation of undistributed earnings and effect of contracts that may be settled in cash or shares (19,269)us-gaap_NetIncomeLossAvailableToCommonStockholdersDiluted
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonClassAMember
1,087us-gaap_NetIncomeLossAvailableToCommonStockholdersDiluted
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonClassAMember
Number of shares used in basic computation 36,217us-gaap_WeightedAverageNumberOfSharesOutstandingBasic
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonClassAMember
36,081us-gaap_WeightedAverageNumberOfSharesOutstandingBasic
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonClassAMember
Conversion of Class B to Class A common shares outstanding 3,159gncma_IncrementalCommonSharesAttributableToConversionFromOneClassOfCommonStockToAnother
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonClassAMember
3,163gncma_IncrementalCommonSharesAttributableToConversionFromOneClassOfCommonStockToAnother
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonClassAMember
Unexercised stock options 0us-gaap_IncrementalCommonSharesAttributableToShareBasedPaymentArrangements
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonClassAMember
118us-gaap_IncrementalCommonSharesAttributableToShareBasedPaymentArrangements
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonClassAMember
Number of shares used in per share computation 39,376us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonClassAMember
39,362us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonClassAMember
Diluted net income (loss) attributable to GCI common stockholders per common share $ (0.49)us-gaap_EarningsPerShareDiluted
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonClassAMember
$ 0.03us-gaap_EarningsPerShareDiluted
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonClassAMember
Common Stock - Class B [Member]    
Class of Stock [Line Items]    
Allocation of undistributed earnings (loss) for basic computation (1,546)gncma_UndistributedIncomeLossAvailabletoCommonStockholders
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonClassBMember
88gncma_UndistributedIncomeLossAvailabletoCommonStockholders
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonClassBMember
Reallocation of undistributed earnings (loss) as a result of conversion of Class B to Class A shares 0gncma_DilutiveSecuritiesEffectOnBasicEarningsPerShareConversionofCommonStock
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonClassBMember
0gncma_DilutiveSecuritiesEffectOnBasicEarningsPerShareConversionofCommonStock
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonClassBMember
Net income (loss) adjusted for allocation of undistributed earnings and effect of contracts that may be settled in cash or shares $ (1,546)us-gaap_NetIncomeLossAvailableToCommonStockholdersDiluted
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonClassBMember
$ 88us-gaap_NetIncomeLossAvailableToCommonStockholdersDiluted
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonClassBMember
Number of shares used in basic computation 3,159us-gaap_WeightedAverageNumberOfSharesOutstandingBasic
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonClassBMember
3,163us-gaap_WeightedAverageNumberOfSharesOutstandingBasic
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonClassBMember
Conversion of Class B to Class A common shares outstanding 0gncma_IncrementalCommonSharesAttributableToConversionFromOneClassOfCommonStockToAnother
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonClassBMember
0gncma_IncrementalCommonSharesAttributableToConversionFromOneClassOfCommonStockToAnother
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonClassBMember
Unexercised stock options 0us-gaap_IncrementalCommonSharesAttributableToShareBasedPaymentArrangements
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonClassBMember
0us-gaap_IncrementalCommonSharesAttributableToShareBasedPaymentArrangements
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonClassBMember
Number of shares used in per share computation 3,159us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonClassBMember
3,163us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonClassBMember
Diluted net income (loss) attributable to GCI common stockholders per common share $ (0.49)us-gaap_EarningsPerShareDiluted
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonClassBMember
$ 0.03us-gaap_EarningsPerShareDiluted
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonClassBMember