Restructuring Charges (Narrative) (Details) $ in Thousands	1 Months Ended	3 Months Ended	12 Months Ended
	Sep. 30, 2014 USD ($) employees	Jul. 02, 2016 employee	Sep. 30, 2016 USD ($)	Sep. 30, 2015 USD ($) employee	Sep. 30, 2014 USD ($)
Restructuring Cost and Reserve [Line Items]
Restructuring charges			$ 76,273	$ 43,409	$ 28,406
Number of employees associated with costs | employees	283
Employee Severance And Related Benefits
Restructuring Cost and Reserve [Line Items]
Restructuring charges			74,929	41,997	27,918
Facility Closures and Other Costs
Restructuring Cost and Reserve [Line Items]
Restructuring charges			1,344	$ 1,412	488
Restructuring Plan 2016
Restructuring Cost and Reserve [Line Items]
Restructuring charges			76,900
Restructuring and Related Cost, Number of Positions Eliminated | employee		810
Restructuring Plan 2016 | Employee Severance And Related Benefits
Restructuring Cost and Reserve [Line Items]
Restructuring charges			74,900
Restructuring Plan 2016 | Facility Closures and Other Costs
Restructuring Cost and Reserve [Line Items]
Restructuring charges			1,300
Restructuring Plan 2015
Restructuring Cost and Reserve [Line Items]
Restructuring charges			600
Restructuring and Related Cost, Number of Positions Eliminated | employee				411
Restructuring Plan 2015 | Employee Severance And Related Benefits
Restructuring Cost and Reserve [Line Items]
Restructuring charges				$ 42,000
Restructuring Plan 2015 | Facility Closures and Other Costs
Restructuring Cost and Reserve [Line Items]
Restructuring charges				1,400
Operating Leases, Rent Expense, Minimum Rentals				2,300
Operating Leases, Sublease Revenue				$ 900
Restructuring Plan 2014
Restructuring Cost and Reserve [Line Items]
Restructuring charges	$ 26,800
Restructuring Plan 2013
Restructuring Cost and Reserve [Line Items]
Restructuring charges					$ 1,600
Maximum [Member] | Restructuring Plan 2016
Restructuring Cost and Reserve [Line Items]
Restructuring charges			$ 80,000