Stockholder's Equity (Narratives) (Details) - USD ($) $ / shares in Units, $ in Millions		12 Months Ended
	Aug. 01, 1997	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Common Stock
Proceeds from Issuance Initial Public Offering	$ 206.6
Share-Based Compensation
Fair value assumptions, method used		The fair value of restricted stock awards is determined based on the number of shares granted and the quoted price of GCI's common stock.
Share-based compensation expense		$ 10.9	$ 8.4	$ 6.6
Unrecognized share-based compensation expense		9.6
GCI 401(k) Plan
Matching contributions		$ 9.8	$ 9.1	$ 8.2
Class A Common Stock
Common Stock
Common stock, shares issued	100	100	100
Restricted Stock
Share-Based Compensation
Weighted average period for recognition of unvested shares		1 year 10 months 2 days
Stock Options
Share-Based Compensation
Vesting period		5 years
Expiration period		10 years
Maximum | Restricted Stock
Share-Based Compensation
Vesting period		3 years
Stock Option Plan [Member] | Class A Common Stock
Share-Based Compensation
Number of shares authorized		15,700,000.0
Number of shares available for grant		2,100,000
Stock Option Plan [Member] | Restricted Stock
Share-Based Compensation
Granted (USD per share)		$ 15.06	$ 10.04	$ 8.30
Fair value of awards vesting		$ 17.0	$ 8.5	$ 5.5
Stock Option Plan [Member] | Stock Options
Share-Based Compensation
Intrinsic values of options exercised		$ 3.8	$ 0.1	$ 0.2