Note 12 - Commitments and Contingencies (Details Textual) - USD ($) $ in Millions	3 Months Ended	6 Months Ended
Jun. 30, 2017	Jun. 30, 2017
GHC [Member]
Employee Medical and Worker's Compensation Claims Expense	$ 0.1	$ 0.3

Aggregate costs and reimbursements paid for employee medical and worker's compensation claims.

No definition available.

Name:	cabo_EmployeeMedicalAndWorkersCompensationClaimsExpense
Namespace Prefix:	cabo_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration