Employee Benefit Plans (Narrative) (Details) (USD $)	1 Months Ended	3 Months Ended		9 Months Ended		10 Months Ended
	Oct. 31, 2012	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011	Oct. 31, 2012
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan employer contribution	$ 8,400,000					$ 51,400,000
Defined contribution plan expense		12,000,000	8,400,000	37,600,000	26,200,000
Number of shares of treasury stock used to fund in defined contribution retirement plan					461,151
Repurchased common stock issued under defined contribution plan				$ 0	$ 17,307,000