Basis of Presentation (Narrative) (Details)	6 Months Ended
	Jun. 30, 2017 market country	Dec. 31, 2016
Telenet [Member]
Basis of Presentation [Line Items]
Percentage ownership in subsidiary	57.30%
Liberty Puerto Rico [Member]
Basis of Presentation [Line Items]
Percentage ownership in subsidiary	60.00%
VodafoneZiggo JV [Member]
Basis of Presentation [Line Items]
Ownership percentage		50.00%
Cable & Wireless Communications Limited (CWC) [Member] | The Bahamas Telecommunications Company Limited [Member]
Basis of Presentation [Line Items]
Percentage ownership in subsidiary	49.00%
Cable & Wireless Communications Limited (CWC) [Member] | Cable & Wireless Jamaica Limited [Member]
Basis of Presentation [Line Items]
Percentage ownership in subsidiary	82.00%
Cable & Wireless Communications Limited (CWC) [Member] | Cable & Wireless Panama, SA [Member]
Basis of Presentation [Line Items]
Percentage ownership in subsidiary	49.00%
Cable & Wireless Communications Limited (CWC) [Member] | Cable & Wireless (Barbados) Limited [Member]
Basis of Presentation [Line Items]
Percentage ownership in subsidiary	81.10%
Video, Broadband Internet and FIxed-Line Telephony, Mobile and other Communications Services [Member]
Basis of Presentation [Line Items]
Number of countries in which entity provides services	30
Sub-Sea Networks [Member] | Cable & Wireless Communications Limited (CWC) [Member]
Basis of Presentation [Line Items]
Number of markets | market	40
Total European Operations Division | Consumer and Business-to-Business Services [Member]
Basis of Presentation [Line Items]
Number of countries in which entity provides services	7
Latin America and the Caribbean [Member] | Consumer and Business-to-Business Services [Member]
Basis of Presentation [Line Items]
Number of countries in which entity provides services	18