Condensed Consolidated Statements of Operations (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Income Statement [Abstract]
Operating Revenues	$ 732,257	$ 692,199
Operating Costs and Expenses [Abstract]
Operating	497,427	451,355
Selling, general and administrative	179,475	174,258
Depreciation of property, plant and equipment	16,704	13,523
Amortization of intangible assets	14,165	13,060
Goodwill and Intangible Asset Impairment	16,401	0
Total Operating Costs and Expenses	724,172	652,196
Income from Operations	8,085	40,003
Equity in (losses) earnings of affiliates, net	(1,547)	1,679
Interest income	1,151	1,700
Interest expense	(7,678)	(7,425)
Non-operating pension and postretirement benefit income, net	18,403	19,928
(Loss) gain on marketable equity securities, net	(100,393)	24,066
Other income, net	2,688	29,351
(Loss) Income Before Income Taxes	(79,291)	109,302
(Benefit from) Provision for Income Taxes	(45,400)	27,600
Net (Loss) Income	(33,891)	81,702
Net Loss Attributable to Noncontrolling Interests	646	46
Net (Loss) Income Attributable to Graham Holdings Company Common Stockholders	$ (33,245)	$ 81,748
Per Share Information Attributable to Graham Holdings Company Common Stockholders
Basic net (loss) income per common share in dollars per share	$ (6.32)	$ 15.38
Basic average number of common shares outstanding in shares	5,274	5,284
Diluted net (loss) income per common share in dollars per share	$ (6.32)	$ 15.26
Diluted average number of common shares outstanding in shares	5,274	5,326