Schedule II - Valuation and Qualifying Accounts and Reserves (Details) - USD ($) $ in Thousands		12 Months Ended
		May 31, 2016	May 31, 2015	May 31, 2014
Allowance for Doubtful Accounts
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Year		$ 15,674	$ 14,906	$ 15,855
Charged to Costs and Expense	[1]	8,646	5,718	5,607
Deductions	[2]	4,716	4,950	6,556
Balance at End of Year		19,604	15,674	14,906
Reserve for Obsolete Inventory
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Year		30,707	30,673	29,487
Charged to Costs and Expense	[1]	5,219	3,278	3,147
Deductions	[2]	3,010	3,244	1,961
Balance at End of Year		$ 32,916	$ 30,707	$ 30,673

[1] Represents amounts charged to expense to increase reserve for estimated future bad debts or to increase reserve for obsolete inventory. Amounts related to inventory are computed by performing a thorough analysis of future marketability by specific inventory item as well as an estimate based on Cintas' historical rates of obsolesence.

[2] Represents reductions in the balance sheet reserve due to the actual write-off of non-collectible accounts receivable or the physical disposal of obsolete inventory items. These amounts do not impact Cintas' consolidated income statement.