Earnings Per Share (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
Earnings Per Share [Line Items]
Income from continuing operations attributable to The Washington Post Company common stockholders	$ 56,016	$ 52,295	$ 25,942	$ (51,039)	$ 56,257	$ 41,550	$ 24,322	$ 134,253	$ 122,129	$ 71,090	$ 150,464
Less: Amount attributable to participating securities	(1,444)				(1,117)			(3,462)	(2,398)
Basic income from continuing operations attributable to The Washington Post Company common stockholders	54,572				55,140			130,791	119,731
Plus: Amount attributable to participating securities	1,444				1,117			3,462	2,398
Diluted income from continuing operations attributable to The Washington Post Company common stockholders	$ 56,016				$ 56,257			$ 134,253	$ 122,129
Basic weighted average shares outstanding	7,231				7,272			7,229	7,405
Diluted weighted average shares outstanding	7,337				7,376			7,316	7,508
Income Per Share From Continuing Operations To Common Stockholders [Abstract]
Basic	$ 7.55	$ 7.05	$ 3.50	$ (7.35)	$ 7.58	$ 5.48	$ 3.17	$ 18.09	$ 16.17	$ 9.22	$ 19.03
Diluted	$ 7.53	$ 7.05	$ 3.50	$ (7.35)	$ 7.58	$ 5.48	$ 3.17	$ 18.07	$ 16.17	$ 9.22	$ 19.03
Stock Option Plan [Member]
Earnings Per Share [Line Items]
Plus: Effect of dilutive shares related to stock options and restricted stock	15				0			8	0
Restricted Stock Awards [Member]
Earnings Per Share [Line Items]
Plus: Effect of dilutive shares related to stock options and restricted stock	91				104			79	103