Consolidated Statements of Comprehensive Income (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Statement of Comprehensive Income [Abstract]
Net Income	$ 1,293,260	$ 237,345	$ 132,187
Foreign currency translation adjustments:
Translation adjustments arising during the year	(16,061)	(1,059)	5,622
Adjustment for sales of businesses with foreign operations	(404)	0	(888)
Total foreign currency translation adjustments	(16,465)	(1,059)	4,734
Unrealized gains on available-for-sale securities:
Unrealized gains for the year	62,719	95,629	33,098
Reclassification adjustment for realization of (gain) loss on exchange, sale or write-down of available-for-sale securities included in net income	(265,274)	9,554	17,226
Total unrealized gains (losses) on available-for-sale securities	(202,555)	105,183	50,324
Pension and other postretirement plans:
Actuarial (loss) gain	(149,482)	762,806	82,470
Prior service cost	(1,600)	0	0
Amortization of net actuarial (gain) loss included in net income	(29,412)	3,096	9,368
Amortization of net prior service credit included in net income	(407)	(1,383)	(1,859)
Curtailments and settlements	8	(124,051)	0
Other adjustments	0	0	(745)
Total pension and other postretirement plans	(180,893)	640,468	89,234
Cash flow hedge gain (loss)	867	520	(1,581)
Other Comprehensive (Loss) Income, Before Tax	(399,046)	745,112	142,711
Income tax benefit (expense) related to items of other comprehensive (loss) income	153,032	(298,472)	(55,186)
Other Comprehensive (Loss) Income, Net of Tax	(246,014)	446,640	87,525
Comprehensive Income	1,047,246	683,985	219,712
Comprehensive loss (income) attributable to noncontrolling interests	583	(503)	(103)
Total Comprehensive Income Attributable to Graham Holdings Company	$ 1,047,829	$ 683,482	$ 219,609