Common Stock (details) (USD $)	9 Months Ended
	Sep. 30, 2012
Common Stock, Number of Shares, Par Value and Other Disclosures [Abstract]
Aggregate Authorized Shares To Repurchase	2,800,000
Aggregate Authorized Value Of Shares To Repurchase	$ 100,000,000
Treasury Stock Program	$ 83,000,000
Treasury Stock, Shares	2,100,000
Date Through Which Entity May Repurchase Stock Under Board Authorization	May 2013