Annual report pursuant to Section 13 and 15(d)

Summary of Significant Accounting Policies (Disaggregation of Revenue) (Details)

v3.10.0.1
Summary of Significant Accounting Policies (Disaggregation of Revenue) (Details) - USD ($)
$ in Thousands
3 Months Ended 12 Months Ended
Dec. 31, 2018
Sep. 30, 2018
Jun. 30, 2018
Mar. 31, 2018
Dec. 31, 2017
Sep. 30, 2017
Jun. 30, 2017
Mar. 31, 2017
Dec. 31, 2018
Dec. 31, 2017
Dec. 31, 2016
Disaggregation of Revenue [Line Items]                      
Total $ 234,922 $ 210,146 $ 233,490 $ 61,204 $ 8,178 $ 5,493 $ 6,177 $ 3,969 $ 739,762 $ 23,817 $ 22,552
Lease, grant, and revenue from subsidies                      
Disaggregation of Revenue [Line Items]                      
Total                 79,672    
GCI Holdings | Consumer Revenue | Wireless                      
Disaggregation of Revenue [Line Items]                      
Revenues                 63,482    
GCI Holdings | Consumer Revenue | Data                      
Disaggregation of Revenue [Line Items]                      
Revenues                 223,121    
GCI Holdings | Consumer Revenue | Video                      
Disaggregation of Revenue [Line Items]                      
Revenues                 16,786    
GCI Holdings | Consumer Revenue | Voice                      
Disaggregation of Revenue [Line Items]                      
Revenues                 19,820    
GCI Holdings | Business Revenue | Wireless                      
Disaggregation of Revenue [Line Items]                      
Revenues                 94,713    
GCI Holdings | Business Revenue | Data                      
Disaggregation of Revenue [Line Items]                      
Revenues                 130,631    
GCI Holdings | Business Revenue | Video                      
Disaggregation of Revenue [Line Items]                      
Revenues                 72,826    
GCI Holdings | Business Revenue | Voice                      
Disaggregation of Revenue [Line Items]                      
Revenues                 14,791    
Evite                      
Disaggregation of Revenue [Line Items]                      
Revenues                 $ 23,920