Subsequent Event (Details) (USD $)	1 Months Ended
	Nov. 05, 2012
Subsequent Event [Line Items]
Shares of Common Stock Repurchased Between Period End Date and Filing Date	157,772
Shares of Common Stock Repurchase Executed Before the Balance Sheet Date but Settled After the Balance Sheet Date	23,671
Average Price Per Share of Common Stock Repurchased Between Period End Date and Filing Date	$ 42.73