Fair Value Measurements (Details) - USD ($) $ in Thousands	Sep. 30, 2016	Sep. 30, 2015
Liabilities
Long-term debt	$ 1,800,000	$ 1,800,000
Unamortized debt issuance costs	18,113	15,276
Fair value measurement on recurring basis | Total
Assets
Cash equivalents (a)		46,003
Total assets		46,325
Liabilities
Long-term debt (c)	1,899,749	1,873,620
Total liabilities	1,900,021	1,873,678
Foreign exchange contracts | Fair value measurement on recurring basis | Total
Assets
Foreign exchange contracts (b)		322
Liabilities
Foreign exchange contracts (b)	272	58
Level 1 | Fair value measurement on recurring basis
Assets
Cash equivalents (a)		46,003
Total assets		46,003
Liabilities
Long-term debt (c)	1,897,625	1,870,750
Total liabilities	1,897,625	1,870,750
Level 2 | Fair value measurement on recurring basis
Assets
Total assets		322
Liabilities
Long-term debt (c)	2,124	2,870
Total liabilities	2,396	2,928
Level 2 | Foreign exchange contracts | Fair value measurement on recurring basis
Assets
Foreign exchange contracts (b)		322
Liabilities
Foreign exchange contracts (b)	272	58
ABL facility
Liabilities
Long-term debt (c)	1,807,700	1,809,400
Unamortized debt issuance costs	$ 23,700	$ 21,800