Stock Repurchase Program (Details) (USD $) In Millions, except Share data, unless otherwise specified	1 Months Ended	3 Months Ended	9 Months Ended	23 Months Ended	0 Months Ended	3 Months Ended	7 Months Ended	23 Months Ended
	Aug. 31, 2011	Sep. 30, 2013	Jun. 30, 2013	Jun. 30, 2013	Aug. 16, 2011 Accelerated Share Repurchase	Sep. 30, 2011 Accelerated Share Repurchase	Mar. 07, 2012 Accelerated Share Repurchase	Jun. 30, 2013 Rule 10b5-1 Repurchase Plan and Open Market Purchases
Stock Repurchase Program
Authorized amount of stock repurchase	$ 200		$ 1,000		$ 100
Stock repurchase additional authorized amount			800
Shares repurchased and retired under the agreement				24,600,000		4,300,000	4,800,000	19,800,000
Total cost of shares repurchased under the agreement				573.7				473.7
Remaining repurchase amount of shares pursuant to the plan			$ 426.3
Average price per share of stock repurchased under the agreement (in dollars per share)				$ 23.35			$ 20.97	$ 23.93
Shares repurchased in transactions that were settled in fiscal quarter four of 2013		200,000