Acquisitions (Unaudited Pro Forma Information) (Details) - USD ($) $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Verizon Transaction
Business Acquisition [Line Items]
Revenue	$ 10,255	$ 11,157
Operating income	1,433	1,529
Net income attributable to Frontier common shareholders	$ 262	$ (192)
Basic and diluted net income per share attributable to Frontier common shareholders	$ (0.23)	$ (0.17)
Connecticut Transaction
Business Acquisition [Line Items]
Revenue		$ 5,775
Operating income		985
Net income attributable to Frontier common shareholders		$ 191
Basic and diluted net income per share attributable to Frontier common shareholders		$ 0.19