Assets And Liabilities Measured At Fair Value Realized Unrealized Gain Loss (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Realized and unrealized gains (losses) on financial instruments, net	$ 116	$ 343	$ 817	$ 336
Fair Value Option Securities - AFS
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Realized and unrealized gain (losses) AFS	162	212	422	348
Fair Value Option Securities - Liberty Broadband
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Realized and unrealized gains (losses) on financial instruments, net	15	161	541	161
Exchangeable Senior Debentures
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Realized and unrealized gains (losses) on financial instruments, net	(55)	(33)	(139)	(175)
Other Financial Instruments
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Realized and unrealized gains (losses) on financial instruments, net	$ (6)	$ 3	$ (7)	$ 2