Employee Benefit Plans (Narrative) (Details) (USD $)	0 Months Ended	3 Months Ended	9 Months Ended				12 Months Ended	3 Months Ended		9 Months Ended
	Apr. 30, 2009	Mar. 31, 2009	Sep. 30, 2011	Sep. 30, 2010	Sep. 30, 2011 Maximum [Member]	Sep. 30, 2011 Minimum [Member]	Dec. 31, 2011 Qualified Pension Plans [Member]	Sep. 30, 2011 Defined Contribution Retirement Plans [Member]	Sep. 30, 2010 Defined Contribution Retirement Plans [Member]	Sep. 30, 2011 Defined Contribution Retirement Plans [Member]	Sep. 30, 2010 Defined Contribution Retirement Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Discretionary contributions							$ 3,500,000
Defined benefit plan expense								8,500,000	9,100,000	26,200,000	28,300,000
Repurchased common stock issued under defined contribution plan			17,307,000	27,383,000						461,151	826,504
Defined benefit plan employer contribution							$ 62,600,000			$ 17,300,000	$ 27,400,000
Percentage of reduction in salaries and wages		5.00%
Reduction in compensated-absences benefit		25.00%
Limited basic contribution in percentage	3.00%				5.00%	3.00%
Limited transition contribution in percentage					3.00%	1.00%