Debt and Capital Lease Obligations - Revolving Credit Facility (Details)			6 Months Ended
	Mar. 31, 2017 USD ($) equity_cure	Mar. 30, 2017 USD ($) equity_cure	Jul. 31, 2017 USD ($)	Jan. 31, 2017 USD ($)
Line of Credit Facility [Line Items]
Minimum Interest Coverage Ratio			0.80
Minimum cash recovery percentage			4.45%
Amount of notes issued			$ 1,114,650,000
Deferred debt issuance costs			6,827,000	$ 10,853,000
Second quarter of fiscal 2017 through the first quarter of fiscal 2018 [Member]
Line of Credit Facility [Line Items]
Minimum cash recovery percentage	4.45%	4.50%
Second quarter of fiscal 2018 through the third quarter of fiscal 2019 [Member]
Line of Credit Facility [Line Items]
Minimum cash recovery percentage	4.20%	4.25%
Revolving Credit Facility [Member]
Line of Credit Facility [Line Items]
Deferred debt issuance costs			6,700,000	$ 5,700,000
Line of Credit [Member] | Letter of Credit [Member]
Line of Credit Facility [Line Items]
Amount of notes issued			$ 40,000,000.0
Line of Credit [Member] | Revolving Credit Facility [Member]
Line of Credit Facility [Line Items]
Maximum capacity extended under credit facility	$ 750,000,000	$ 810,000,000
Debt Instrument, Number of Equity Cures Exercisable | equity_cure	2	1
Maximum amount of each equity cure	$ 20,000,000	$ 10,000,000
Weighted-average interest rate			6.90%
Write off debt issuance costs	300,000
Deferred debt issuance costs	$ 2,800,000
Line of Credit [Member] | Revolving Credit Facility [Member] | Second quarter of fiscal 2017 through the first quarter of fiscal 2018 [Member]
Line of Credit Facility [Line Items]
Minimum Interest Coverage Ratio	0.80
Line of Credit [Member] | Revolving Credit Facility [Member] | Second quarter of fiscal 2018 through the third quarter of fiscal 2019 [Member]
Line of Credit Facility [Line Items]
Minimum Interest Coverage Ratio	1.10
Line of Credit [Member] | Revolving Credit Facility [Member] | May 31, 2016 through June 30, 2017 [Member]
Line of Credit Facility [Line Items]
Minimum Interest Coverage Ratio	1.25
Minimum [Member] | Line of Credit [Member] | Revolving Credit Facility [Member]
Line of Credit Facility [Line Items]
Unused capacity fee percentage			0.25%
Maximum [Member] | Line of Credit [Member] | Revolving Credit Facility [Member]
Line of Credit Facility [Line Items]
Unused capacity fee percentage			0.75%
LIBOR [Member] | Line of Credit [Member] | Revolving Credit Facility [Member]
Line of Credit Facility [Line Items]
Variable basis spread			1.00%
Alternate Base Rate [Member] | Line of Credit [Member] | Revolving Credit Facility [Member]
Line of Credit Facility [Line Items]
Variable basis spread	2.50%
Alternate Base Rate [Member] | Minimum [Member] | Line of Credit [Member] | Revolving Credit Facility [Member]
Line of Credit Facility [Line Items]
Variable basis spread			1.75%
Alternate Base Rate [Member] | Maximum [Member] | Line of Credit [Member] | Revolving Credit Facility [Member]
Line of Credit Facility [Line Items]
Variable basis spread			2.25%
Federal Funds Rate [Member] | Line of Credit [Member] | Revolving Credit Facility [Member]
Line of Credit Facility [Line Items]
Variable basis spread			0.50%
Revolving Credit Facility [Member]
Line of Credit Facility [Line Items]
Line Of Credit Facility Additional Remaining Borrowing Capacity			$ 416,800,000
Sub-facility for letters of credit			2,800,000
Line of Credit Facility, Remaining Borrowing Capacity			$ 130,500,000
Revolving Credit Facility [Member] | LIBOR [Member]
Line of Credit Facility [Line Items]
Variable basis spread	3.50%
Revolving Credit Facility [Member] | LIBOR [Member] | Minimum [Member]
Line of Credit Facility [Line Items]
Variable basis spread			2.75%
Revolving Credit Facility [Member] | LIBOR [Member] | Maximum [Member]
Line of Credit Facility [Line Items]
Variable basis spread			3.25%