Investments in Affiliates Accounted for Using the Equity Method (Summary of Financial Information) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019	Mar. 31, 2020	Dec. 31, 2019	Mar. 31, 2019	Dec. 31, 2018
Schedule of Equity Method Investments [Line Items]
Current assets	$ 220,864		$ 220,864			$ 246,587
Investments in affiliates	167,121		167,121			167,643
Other assets	339,733		339,733			295,693
Total assets	11,373,622		11,373,622			11,356,020
Long-term debt	2,602,295		2,602,295			2,604,371
Deferred income tax liabilities	1,586,519		1,586,519			1,578,643
Other liabilities	118,744		118,744			133,020
Equity	6,528,484	$ 5,763,224	6,528,484	$ 5,763,224	$ 5,868,203	6,506,069	$ 5,247,535	$ 4,488,017
Total liabilities and shareholders' equity	11,373,622		11,373,622			11,356,020
Operating expenses, net	(222,014)	(233,030)	(446,579)	(482,228)
Operating income (loss)	2,806	(15,464)	14,040	(46,926)
Share of earnings (loss) of affiliates, net	2,238	(1,068)	1,531	(4,364)
Realized and unrealized gains (losses) on financial instruments, net	922,910	744,170	67,408	1,848,605
Other income (expense), net	893,957	716,572	6,266	1,784,954
Income tax benefit (expense)	(245,021)	(192,958)	(8,629)	(479,705)
Net earnings (loss)	$ 651,768	508,150	$ 11,728	1,258,380
Liberty Broadband
Schedule of Equity Method Investments [Line Items]
Equity Method Investment, Ownership Percentage	23.50%		23.50%
Current assets	$ 19,706		$ 19,706			52,133
Investments in affiliates	12,306,593		12,306,593			12,194,674
Other assets	9,100		9,100			9,535
Total assets	12,335,399		12,335,399			12,256,342
Long-term debt	573,593		573,593			572,944
Deferred income tax liabilities	1,017,921		1,017,921			999,757
Other liabilities	23,151		23,151			15,695
Equity	10,720,734		10,720,734			10,667,946
Total liabilities and shareholders' equity	12,335,399		12,335,399			$ 12,256,342
Revenues	4,114	3,747	8,218	7,205
Operating expenses, net	(13,946)	(10,913)	(25,325)	(20,572)
Operating income (loss)	(9,832)	(7,166)	(17,107)	(13,367)
Share of earnings (loss) of affiliates, net	158,128	45,400	219,810	80,249
Gain (loss) on dilution of investment in affiliate	(46,001)	(16,322)	(105,326)	(57,725)
Other income (expense), net	(5,103)	(5,936)	(10,801)	(12,056)
Income tax benefit (expense)	(24,978)	(3,924)	(22,204)	650
Net earnings (loss)	$ 72,214	$ 12,052	$ 64,372	$ (2,249)