Summary of Quarterly Operating Results and Comprehensive Income (Unaudited) (Quarterly Results) (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended							9 Months Ended		12 Months Ended
	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Sep. 30, 2013	Sep. 30, 2012	Dec. 31, 2012	Dec. 31, 2011
Operating Revenues [Abstract]
Education	$ 546,452	$ 548,230	$ 527,815	$ 546,341	$ 551,696	$ 551,774	$ 546,685	$ 1,622,497	$ 1,650,155	$ 2,196,496	$ 2,404,459
Advertising	84,444	96,670	82,994	117,696	105,855	94,649	82,600	264,108	283,104	400,800	327,877
Subscriber and circulation	190,302	192,273	186,790	186,383	185,326	182,639	178,022	569,365	545,987	732,370	710,253
Other	81,281	52,423	39,241	45,471	34,760	25,368	20,305	172,945	80,433	125,904	83,408
Total operating revenues	902,479	889,596	836,840	895,891	877,637	854,430	827,612	2,628,915	2,559,679	3,455,570	3,525,997
Operating Costs and Expenses [Abstract]
Operating	430,889	400,515	381,965	389,620	407,364	387,167	382,106	1,213,369	1,176,637	1,566,257	1,562,615
Selling, general and administrative	331,247	323,182	337,865	336,262	314,359	335,054	347,841	992,294	997,254	1,333,516	1,383,660
Depreciation of property, plant and equipment	55,633	57,816	59,895	73,731	57,588	56,594	56,165	173,344	170,347	244,078	223,403
Amortization of intangible assets	2,837	3,313	3,717	7,610	5,090	4,407	3,839	9,867	13,336	20,946	22,201
Impairment of goodwill and other long-lived assets				111,593		0	0			111,593	0
Total operating costs and expenses	820,606	784,826	783,442	918,816	784,401	783,222	789,951	2,388,874	2,357,574	3,276,390	3,191,879
Income (Loss) from Operations	81,873	104,770	53,398	(22,925)	93,236	71,208	37,661	240,041	202,105	179,180	334,118
Equity in earnings of affiliates, net	5,892	3,868	3,418	2,785	4,099	3,314	3,888	13,178	11,301	14,086	5,949
Interest income	642	522	510	901	648	775	1,069	1,674	2,492	3,393	4,147
Interest expense	(9,221)	(9,048)	(8,960)	(9,064)	(8,738)	(8,979)	(9,163)	(27,229)	(26,880)	(35,944)	(33,226)
Other income (expense), net	8,110	(12,858)	(4,083)	(17,572)	4,163	(635)	8,588	(8,831)	12,116	(5,456)	(55,200)
Income from Continuing Operations Before Income Taxes	87,296	87,254	44,283	(45,875)	93,408	65,683	42,043	218,833	201,134	155,259	255,788
Provision for Income Taxes	31,000	34,500	17,800	5,100	37,000	23,900	17,200	83,300	78,100	83,200	104,400
Income (Loss) from Continuing Operations	56,296	52,754	26,483	(50,975)	56,408	41,783	24,843	135,533	123,034	72,059	151,388
(Loss) Income from Discontinued Operations, Net of Tax	(25,872)	(7,620)	(21,224)	5,600	37,539	10,264	6,725	(54,716)	54,528	60,128	(34,231)
Net Income (Loss)	30,424	45,134	5,259	(45,375)	93,947	52,047	31,568	80,817	177,562	132,187	117,157
Net (Income) Loss Attributable to Noncontrolling Interests	(75)	(253)	(97)	(64)	71	(11)	(70)	(425)	(10)	(74)	(7)
Net Income (Loss) Attributable to The Washington Post Company	30,349	44,881	5,162	(45,439)	94,018	52,036	31,498	80,392	177,552	132,113	117,150
Redeemable Preferred Stock Dividends	(205)	(206)	(444)	0	(222)	(222)	(451)	(855)	(895)	(895)	(917)
Net Income (Loss) Attributable to The Washington Post Company Common Stockholders	30,144	44,675	4,718	(45,439)	93,796	51,814	31,047	79,537	176,657	131,218	116,233
Amounts Attributable to The Washington Post Company Common Stockholders
Income from continuing operations	56,016	52,295	25,942	(51,039)	56,257	41,550	24,322	134,253	122,129	71,090	150,464
(Loss) income from discontinued operations, net of tax	(25,872)	(7,620)	(21,224)	5,600	37,539	10,264	6,725	(54,716)	54,528	60,128	(34,231)
Net income (loss) attributable to The Washington Post Company common stockholders	$ 30,144	$ 44,675	$ 4,718	$ (45,439)	$ 93,796	$ 51,814	$ 31,047	$ 79,537	$ 176,657	$ 131,218	$ 116,233
Per Share Information Attributable to The Washington Post Company Common Stockholders
Basic income (loss) per common share from continuing operations	$ 7.55	$ 7.05	$ 3.50	$ (7.35)	$ 7.58	$ 5.48	$ 3.17	$ 18.09	$ 16.17	$ 9.22	$ 19.03
Basic (loss) income per common share from discontinued operations	$ (3.48)	$ (1.03)	$ (2.86)	$ 0.78	$ 5.06	$ 1.36	$ 0.90	$ (7.37)	$ 7.22	$ 8.17	$ (4.33)
Basic net income (loss) per common share	$ 4.07	$ 6.02	$ 0.64	$ (6.57)	$ 12.64	$ 6.84	$ 4.07	$ 10.72	$ 23.39	$ 17.39	$ 14.70
Diluted income (loss) per common share from continuing operations	$ 7.53	$ 7.05	$ 3.50	$ (7.35)	$ 7.58	$ 5.48	$ 3.17	$ 18.07	$ 16.17	$ 9.22	$ 19.03
Diluted (loss) income per common share from discontinued operations	$ (3.48)	$ (1.03)	$ (2.86)	$ 0.78	$ 5.06	$ 1.36	$ 0.90	$ (7.37)	$ 7.22	$ 8.17	$ (4.33)
Diluted net income (loss) per common share	$ 4.05	$ 6.02	$ 0.64	$ (6.57)	$ 12.64	$ 6.84	$ 4.07	$ 10.70	$ 23.39	$ 17.39	$ 14.70
Average number of common shares outstanding, basic	7,231				7,272			7,229	7,405
Average number of common shares outstanding, diluted	7,337				7,376			7,316	7,508