Condensed Consolidated Statements of Operations (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Income Statement [Abstract]
Operating Revenues	$ 652,871	$ 737,602	$ 1,385,128	$ 1,429,801
Operating Costs and Expenses [Abstract]
Operating	433,767	481,154	931,194	932,509
Selling, general and administrative	164,476	171,028	343,951	345,286
Depreciation of property, plant and equipment	22,913	13,884	39,617	27,407
Amortization of intangible assets	14,327	12,880	28,492	25,940
Impairment of goodwill and other long-lived assets	11,511	693	27,912	693
Total Operating Costs and Expenses	646,994	679,639	1,371,166	1,331,835
Income from Operations	5,877	57,963	13,962	97,966
Equity in earnings (losses) of affiliates, net	1,182	1,467	(365)	3,146
Interest income	954	1,579	2,105	3,279
Interest expense	(7,377)	(8,386)	(15,055)	(15,811)
Non-operating pension and postretirement benefit income, net	12,136	12,253	30,539	32,181
Gain (loss) on marketable equity securities, net	39,890	7,791	(60,503)	31,857
Other income, net	8,100	1,228	10,788	30,579
Income (Loss) Before Income Taxes	60,762	73,895	(18,529)	183,197
Provision for (Benefit from) Income Taxes	41,900	16,700	(3,500)	44,300
Net Income (Loss)	18,862	57,195	(15,029)	138,897
Net (Income) Loss Attributable to Noncontrolling Interests	(8)	(114)	638	(68)
Net Income (Loss) Attributable to Graham Holdings Company Common Stockholders	$ 18,854	$ 57,081	$ (14,391)	$ 138,829
Per Share Information Attributable to Graham Holdings Company Common Stockholders
Basic net income (loss) per common share in dollars per share	$ 3.61	$ 10.74	$ (2.77)	$ 26.12
Basic average number of common shares outstanding in shares	5,196	5,285	5,235	5,285
Diluted net income (loss) per common share in dollars per share	$ 3.60	$ 10.65	$ (2.77)	$ 25.91
Diluted average number of common shares outstanding in shares	5,201	5,329	5,235	5,328