Stock-based Compensation (Schedule of Restricted Stock Unit Grants For The Period) (Details) shares in Thousands	6 Months Ended
	Mar. 31, 2018 installment shares
TSR Units [Member]
Granted, shares	184
Performance-Based Restricted Stock Units [Member]
Granted, shares	461
Award vesting period	3 years
Number of equal annual installments | installment	3
Service-Based Restricted Stock Units [Member]
Granted, shares	710
Number of equal annual installments | installment	3
Catch-Up Provision [Member] | Maximum | Performance-Based Restricted Stock Units [Member]
Granted, shares	189
No Catch-Up Provision [Member] | Maximum | Performance-Based Restricted Stock Units [Member]
Granted, shares	250