New Accounting Pronouncements (Details)	6 Months Ended
Jun. 30, 2012 statement
New Accounting Pronouncements
Number of separate statements in which the entity is required to present comprehensive income	2

Represents the number of statements presented by the entity to reflect the net income, total net income, components of other comprehensive income and total of other comprehensive income.

No definition available.

Name:	penn_NewAccountingPronouncementOrChangeInAccountingPrincipleNumberOfSeparateStatements
Namespace Prefix:	penn_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration