Stock Repurchases (Details) (USD $)	6 Months Ended		0 Months Ended	1 Months Ended	3 Months Ended	6 Months Ended
	Mar. 31, 2012	Apr. 02, 2011	Aug. 25, 2011 Stock repurchase program, August 25, 2011 [Member] M	Oct. 01, 2011 Stock repurchase program, August 25, 2011 [Member]	Mar. 31, 2012 Stock repurchase program, August 25, 2011 [Member]	Mar. 31, 2012 Stock repurchase program, August 25, 2011 [Member]
Equity, Class of Treasury Stock [Line Items]
Authorized repurchase of common stock			$ 50,000,000
Period of repurchase program from the date of authorization (in months)			12
Payments for Repurchase of Common Stock	20,665,000	27,397,000		25,000,000
Remaining authorized repurchase amount				25,000,000		4,300,000
Number of shares of outstanding common stock repurchased and retired					0	450,500
Average price per share of outstanding common stock repurchased and retired						$ 45.84
Total amount of outstanding common stock repurchased and retired, excluding expenses						$ 20,700,000