Business Segments (Narrative) (Details) (USD $) In Millions, unless otherwise specified	9 Months Ended	3 Months Ended
Sep. 30, 2012 segments	Sep. 30, 2012 Kaplan International [Member] Related To Certain Items Recorded In 2011 And 2010 [Member]
Number of reportable segments	6
Prior periods adjustments		$ 3.9

Amount of effect on financial statements related to corrections of prior year errors in the current year financial statements when the effect of the prior year error was immaterial to the prior year financial statements and the current year correction is immaterial to the current year financial statements.

No definition available.

Name:	wpo_ImmaterialErrorCorrectionAmount
Namespace Prefix:	wpo_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration