Income Taxes - Components of Net Deferred Tax Asset and Liability Accounts (Details) - USD ($) $ in Thousands		Sep. 30, 2018	Sep. 30, 2017
Deferred tax assets:
Interest rate swaps		$ 4,509	$ 14,088
Self-insurance reserves		22,371	34,314
Deferred compensation		2,899	3,860
Deferred rent		190	323
Leases			615
Payroll related accruals		9,934	10,267
Other accrued expenses		2,485	3,864
Allowance for doubtful accounts		1,525	3,340
Net operating loss carryforward		4,460	2,274
Other non-current deferred tax assets		191	378
Total non-current deferred tax assets		48,564	73,323
Total deferred tax assets		48,564	73,323
Deferred tax liabilities:
Intangible assets		68,457	134,490
Property and equipment		35,671	47,037
Inventories		4,123	6,264
Deferred revenue		6,782	10,112
Prepaid assets		137	428
Other non-current deferred tax liabilities		613	131
Total non-current deferred tax liabilities		115,783	198,462
Total deferred tax liabilities	[1]	$ 67,219	$ 125,139

[1] The 2017 Tax Act impacted the comparison of the 2018 to the 2017 deferred tax changes by $43,429 as a result of the U.S. tax rate reduction and the change in the ASC 740-30 deferred liability balance.