Stock-Based Compensation Plans (Details) (USD $)	9 Months Ended
Sep. 30, 2011
Schedule Of Weighted Average Grant Date Fair Value Of Stock Option Awards [Abstract]
Weighted average grant date fair value of stock option awards granted	$ 10.45

The weighted average grant-date fair value of options granted during the reporting period as calculated by applying the disclosed option pricing methodology.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 123R

-Paragraph A240

-Subparagraph c(1)

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Namespace Prefix:	us-gaap
Data Type:	us-types:perShareItemType
Balance Type:	na
Period Type:	duration