Commitments and Contingencies (Details 4) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Sep. 30, 2014 item	Sep. 30, 2013	Sep. 30, 2012
Commitments and Contingencies
Number of employee benefit plans	6
Benefit plan expenses, net	$ 26.7	$ 23.0	$ 31.3
Percentage of compensation as tax-deferred contributions	50.00%
Vesting period for matching contributions	3 years
Percentage of tax-deferred contributions of base compensation	50.00%
Percentage of tax deferred contributions of incentive compensation	100.00%
Number of ICP plans	2
Annual vesting percentage under profit sharing program	20.00%
Participant age at which vesting of employer contribution begins	61
Participant age at which full vesting of employer contribution is complete	65
Employee Share Purchase Plan
Commitments and Contingencies
Shares held in reserve for issuance	4.3
ESPP shares available for future issuance	2.4
Percentage of cost per share of the fair market value at the end of each quarterly offering period	85.00%
Minimum | Employee Share Purchase Plan
Commitments and Contingencies
Percentage of cash compensation	1.00%
Maximum | Employee Share Purchase Plan
Commitments and Contingencies
Percentage of cash compensation	10.00%
Self Insurance
Commitments and Contingencies
Stop-loss coverage per individual per year	0.2
Stop-loss coverage per occurrence	0.25
Annual aggregate stop-loss coverage	6.1
Accrued medical and workers compensation claims	$ 4.8