Equity - Narrative (Details) $ / shares in Units, $ / shares in Units, $ in Millions, $ in Millions, $ in Millions				1 Months Ended	12 Months Ended
	Sep. 09, 2019 USD ($)	Oct. 17, 2018 shares	Dec. 29, 2017 shares	Jun. 30, 2019 USD ($)	Dec. 31, 2019 USD ($) vote $ / shares shares	Dec. 31, 2019 BBD ($) vote	Dec. 31, 2018 JMD ($) $ / shares shares	Dec. 31, 2018 USD ($)	Dec. 31, 2017 USD ($)	Dec. 31, 2016 USD ($)	Dec. 31, 2019 BBD ($) shares	Sep. 30, 2019	Mar. 31, 2019	Sep. 01, 2017 $ / shares	Aug. 31, 2017
Class of Stock [Line Items]
Adjustments to additional paid in capital, capped calls					$ 45.6
Aggregate purchase price					$ 5.1			$ 20.9	$ 32.3
Document Period End Date					Dec. 31, 2019	Dec. 31, 2019
Capital distributions									53.2
Adjustment to additional paid-in capital				$ 77.0
Convertible notes transaction fees and costs					$ 1.0
Liberty Puerto Rico
Class of Stock [Line Items]
Proceeds from contributions from affiliates								45.0
Proceeds from contributions from parent								27.0
Searchlight | Liberty Puerto Rico
Class of Stock [Line Items]
Proceeds from contributions from affiliates								18.0
United Telecommunications Services N.V. (UTS)
Class of Stock [Line Items]
Aggregate purchase price	$ 12.0				5.0
C&W Jamaica
Class of Stock [Line Items]
Percentage ownership in subsidiary							82.00%
Additional interest acquired (in shares) | shares							1,727,047,174
Acquisition share price (in dollars per share) | $ / shares							$ 1.45
Aggregate purchase price							$ 2,504	20.0
C&W Jamaica | C&W
Class of Stock [Line Items]
Percentage ownership in subsidiary							92.30%
Liberty Puerto Rico
Class of Stock [Line Items]
Interest acquired		40.00%
Cable & Wireless (Barbados) Limited
Class of Stock [Line Items]
Percentage ownership in subsidiary														100.00%	81.10%
Acquisition share price (in dollars per share) | $ / shares														$ 2.86
Aggregate purchase price					34.0	$ 67
Transaction fees					1.0	$ 2
Liability recorded					$ 6.0						$ 12
Class A
Class of Stock [Line Items]
Number of votes per share | vote					1	1
Class B
Class of Stock [Line Items]
Number of votes per share | vote					10	10
Conversion ratio					1	1
Class C
Class of Stock [Line Items]
Number of votes per share | vote					0	0
Number of votes per share when required by law | vote					0.01	0.01
Common stock, shares authorized (in shares) | shares					18,100,000						18,100,000
Option indexed to issuer's equity, strike price (in dollars per share) | $ / shares					$ 22.2337
Option indexed to issuer's equity, cap price (in dollars per share) | $ / shares					$ 31.7625
Adjustments to additional paid in capital, capped calls					$ 46.0
United Telecommunications Services N.V. (UTS)
Class of Stock [Line Items]
Interest acquired												87.50%	87.50%
Percentage ownership in subsidiary												100.00%
UTS NCI Acquisition
Class of Stock [Line Items]
Equity interest issued (in shares) | shares		9,500,000
Accumulated net contributions (distributions)
Class of Stock [Line Items]
Capital distributions								$ 53.2	$ 53.2	$ 21.4
Spinoff | Class A
Class of Stock [Line Items]
Distribution shares issued (in shares) | shares			48,428,841
Spinoff | Class B
Class of Stock [Line Items]
Distribution shares issued (in shares) | shares			1,940,193
Spinoff | Class C
Class of Stock [Line Items]
Distribution shares issued (in shares) | shares			120,843,539
Accounts Payable and Accrued Liailities | United Telecommunications Services N.V. (UTS)
Class of Stock [Line Items]
Aggregate purchase price					$ 7.0