Segments (Segment Profitability Definition Adjustment) (Details) - Wireless [Member] - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
Jun. 30, 2016	Mar. 31, 2016	Jun. 30, 2016
Segment Reporting Information [Line Items]
Previously Defined Adjusted EBITDA	$ 40,334	$ 40,064	$ 80,398
Cash Received in Excess of Revenue Recognized	(7,500)	(7,500)	(15,000)
Adjusted EBITDA	$ 32,834	$ 32,564	$ 65,398

Company's specifically defined measure of segment profitability which is defined as earnings plus cash received in excess of revenue recognized for long-term fixed roaming arrangements and imputed interest on financed devices before: Net interest expense, Income taxes, Depreciation and amortization expense, Loss on extinguishment of debt, Software impairment charge, Derivative instrument unrealized income (loss), Share-based compensation expense, Accretion expense, Loss attributable to non-controlling interest resulting from NMTC transactions, Gains and impairment losses on equity and cost method investments, and Other non-cash adjustments.

No definition available.

Name:	gciinc_PreviouslyDefinedAdjustedEBITDA
Namespace Prefix:	gciinc_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration