Condensed Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Income Statement [Abstract]
Operating Revenues	$ 659,436	$ 582,717
Operating Costs and Expenses [Abstract]
Operating	365,151	325,687
Selling, general and administrative	225,045	225,289
Depreciation of property, plant and equipment	14,642	14,652
Amortization of intangible assets	10,384	6,836
Total Operating Costs and Expenses	615,222	572,464
Income from Operations	44,214	10,253
Equity in earnings of affiliates, net	2,579	649
Interest income	1,372	1,363
Interest expense	(8,071)	(8,129)
Non-operating pension and postretirement benefit income, net	21,386	18,801
Loss on marketable equity securities, net	(14,102)	0
Other income, net	9,187	849
Income Before Income Taxes	56,565	23,786
Provision for Income Taxes	13,600	2,700
Net Income	42,965	21,086
Net Income Attributable to Noncontrolling Interests	(74)	0
Net Income Attributable to Graham Holdings Company Common Stockholders	42,891	21,086
Net Income Attributable to Graham Holdings Company Common Stockholders	$ 42,596	$ 20,884
Per Share Information Attributable to Graham Holdings Company Common Stockholders
Basic net income per common share in dollars per share	$ 7.84	$ 3.77
Basic average number of common shares outstanding in shares	5,436	5,535
Diluted net income per common share in dollars per share	$ 7.78	$ 3.75
Diluted average number of common shares outstanding in shares	5,473	5,569