Condensed Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Income Statement [Abstract]
Operating Revenues	$ 692,199	$ 659,436
Operating Costs and Expenses [Abstract]
Operating	477,230	365,151
Selling, general and administrative	148,383	225,045
Depreciation of property, plant and equipment	13,523	14,642
Amortization of intangible assets	13,060	10,384
Total Operating Costs and Expenses	652,196	615,222
Income from Operations	40,003	44,214
Equity in earnings of affiliates, net	1,679	2,579
Interest income	1,700	1,372
Interest expense	(7,425)	(8,071)
Non-operating pension and postretirement benefit income, net	19,928	21,386
Gain (loss) on marketable equity securities, net	24,066	(14,102)
Other income, net	29,351	9,187
Income Before Income Taxes	109,302	56,565
Provision for Income Taxes	27,600	13,600
Net Income	81,702	42,965
Net Loss (Income) Attributable to Noncontrolling Interests	46	(74)
Net Income Attributable to Graham Holdings Company Common Stockholders	$ 81,748	$ 42,891
Per Share Information Attributable to Graham Holdings Company Common Stockholders
Basic net income per common share in dollars per share	$ 15.38	$ 7.84
Basic average number of common shares outstanding in shares	5,284	5,436
Diluted net income per common share in dollars per share	$ 15.26	$ 7.78
Diluted average number of common shares outstanding in shares	5,326	5,473