Supplemental Guarantor Information - Condensed Consolidating Statement of Cash Flows (Details) - USD ($) $ in Thousands	3 Months Ended
	Aug. 31, 2016	Aug. 31, 2015
Cash flows from operating activities:
Net income	$ 138,091	$ 100,181
Adjustments to reconcile net income to net cash provided by (used in) operating activities
Depreciation	39,679	36,165
Amortization of intangible assets	3,489	3,603
Stock-based compensation	20,779	23,917
Gain on Storage transaction	0	(4,843)
Loss on investment in Shred-it Partnership	0	14,516
Deferred income taxes	1,970	5,632
Change in current assets and liabilities, net of acquisitions of businesses:
Accounts receivable, net	(22,946)	(19,255)
Inventories, net	(13,017)	(8,109)
Uniforms and other rental items in service	(1,872)	(4,939)
Prepaid expenses and other current assets	(5,655)	(6,024)
Accounts payable	17,480	15,531
Accrued compensation and related liabilities	(37,276)	(35,579)
Accrued liabilities and other	(23,676)	(26,253)
Income taxes, current	40,542	48,540
Net cash provided by operating activities	157,588	143,083
Cash flows from investing activities:
Capital expenditures	(78,580)	(62,631)
Proceeds from redemption of marketable securities	109,612	152,907
Purchase of marketable securities and investments	(119,729)	(196,020)
Proceeds from Storage transaction	0	24,395
Acquisitions of businesses, net of cash acquired	(10,991)	(121,434)
Other, net	(918)	921
Net cash used in investing activities	(100,606)	(201,862)
Cash flows from financing activities:
Proceeds from issuance of commercial paper, net	163,800	0
Proceeds from issuance of debt	0	0
Repayment of debt	(250,000)	(16)
Prepaid short-term debt financing fees	(8,625)	0
Exercise of stock-based compensation awards	16,282	11,844
Repurchase of common stock	(18,870)	(221,598)
Other, net	385	51
Net cash used in financing activities	(97,028)	(209,719)
Effect of exchange rate changes on cash and cash equivalents	(102)	(1,715)
Net decrease in cash and cash equivalents	(40,148)	(270,213)
Cash and cash equivalents at beginning of period	139,357	417,073
Cash and cash equivalents at end of period	99,209	146,860
Eliminations
Cash flows from operating activities:
Net income	(135,265)	(101,804)
Adjustments to reconcile net income to net cash provided by (used in) operating activities
Depreciation	0	0
Amortization of intangible assets	0	0
Stock-based compensation	0	0
Gain on Storage transaction		0
Loss on investment in Shred-it Partnership		0
Deferred income taxes	0	0
Change in current assets and liabilities, net of acquisitions of businesses:
Accounts receivable, net	0	0
Inventories, net	(2,536)	2,211
Uniforms and other rental items in service	(405)	(577)
Prepaid expenses and other current assets	0	0
Accounts payable	115	(16)
Accrued compensation and related liabilities	0	0
Accrued liabilities and other	0	724
Income taxes, current	0	0
Net cash provided by operating activities	(138,091)	(99,462)
Cash flows from investing activities:
Capital expenditures	0	0
Proceeds from redemption of marketable securities	0	0
Purchase of marketable securities and investments	17,733	4,010
Proceeds from Storage transaction		0
Acquisitions of businesses, net of cash acquired	0	0
Other, net	120,358	96,176
Net cash used in investing activities	138,091	100,186
Cash flows from financing activities:
Proceeds from issuance of commercial paper, net	0
Proceeds from issuance of debt	0	0
Repayment of debt	0	(724)
Prepaid short-term debt financing fees	0
Exercise of stock-based compensation awards	0	0
Repurchase of common stock	0	0
Other, net	0	0
Net cash used in financing activities	0	(724)
Effect of exchange rate changes on cash and cash equivalents	0	0
Net decrease in cash and cash equivalents	0	0
Cash and cash equivalents at beginning of period	0	0
Cash and cash equivalents at end of period	0	0
Cintas Corporation
Cash flows from operating activities:
Net income	138,091	100,181
Adjustments to reconcile net income to net cash provided by (used in) operating activities
Depreciation	0	0
Amortization of intangible assets	0	0
Stock-based compensation	20,779	23,917
Gain on Storage transaction		0
Loss on investment in Shred-it Partnership		0
Deferred income taxes	0	0
Change in current assets and liabilities, net of acquisitions of businesses:
Accounts receivable, net	0	0
Inventories, net	0	0
Uniforms and other rental items in service	0	0
Prepaid expenses and other current assets	0	0
Accounts payable	0	0
Accrued compensation and related liabilities	0	0
Accrued liabilities and other	0	0
Income taxes, current	0	0
Net cash provided by operating activities	158,870	124,098
Cash flows from investing activities:
Capital expenditures	0	0
Proceeds from redemption of marketable securities	0	0
Purchase of marketable securities and investments	0	0
Proceeds from Storage transaction		0
Acquisitions of businesses, net of cash acquired	0	0
Other, net	(156,282)	85,656
Net cash used in investing activities	(156,282)	85,656
Cash flows from financing activities:
Proceeds from issuance of commercial paper, net	0
Proceeds from issuance of debt	0	0
Repayment of debt	0	0
Prepaid short-term debt financing fees	0
Exercise of stock-based compensation awards	16,282	11,844
Repurchase of common stock	(18,870)	(221,598)
Other, net	0	0
Net cash used in financing activities	(2,588)	(209,754)
Effect of exchange rate changes on cash and cash equivalents	0	0
Net decrease in cash and cash equivalents	0	0
Cash and cash equivalents at beginning of period	0	0
Cash and cash equivalents at end of period	0	0
Corp. 2
Cash flows from operating activities:
Net income	43,871	31,810
Adjustments to reconcile net income to net cash provided by (used in) operating activities
Depreciation	25,755	22,677
Amortization of intangible assets	3,194	3,513
Stock-based compensation	0	0
Gain on Storage transaction		(4,843)
Loss on investment in Shred-it Partnership		13,427
Deferred income taxes	(1,050)	23
Change in current assets and liabilities, net of acquisitions of businesses:
Accounts receivable, net	(21,693)	(20,532)
Inventories, net	(11,331)	(8,855)
Uniforms and other rental items in service	950	(2,164)
Prepaid expenses and other current assets	(63)	(159)
Accounts payable	(58,018)	31,253
Accrued compensation and related liabilities	(25,961)	(26,303)
Accrued liabilities and other	(2,906)	(2,444)
Income taxes, current	3,163	8,799
Net cash provided by operating activities	(44,089)	46,202
Cash flows from investing activities:
Capital expenditures	(43,130)	(32,661)
Proceeds from redemption of marketable securities	0	0
Purchase of marketable securities and investments	(4,161)	2,215
Proceeds from Storage transaction		24,395
Acquisitions of businesses, net of cash acquired	(905)	(96,353)
Other, net	166,037	55,473
Net cash used in investing activities	117,841	(46,931)
Cash flows from financing activities:
Proceeds from issuance of commercial paper, net	163,800
Proceeds from issuance of debt	0	0
Repayment of debt	(250,000)	(309)
Prepaid short-term debt financing fees	(8,625)
Exercise of stock-based compensation awards	0	0
Repurchase of common stock	0	0
Other, net	385	488
Net cash used in financing activities	(94,440)	179
Effect of exchange rate changes on cash and cash equivalents	0	0
Net decrease in cash and cash equivalents	(20,688)	(550)
Cash and cash equivalents at beginning of period	57,893	74,632
Cash and cash equivalents at end of period	37,205	74,082
Subsidiary Guarantors
Cash flows from operating activities:
Net income	87,515	67,855
Adjustments to reconcile net income to net cash provided by (used in) operating activities
Depreciation	11,441	11,090
Amortization of intangible assets	88	40
Stock-based compensation	0	0
Gain on Storage transaction		0
Loss on investment in Shred-it Partnership		0
Deferred income taxes	3,227	5,782
Change in current assets and liabilities, net of acquisitions of businesses:
Accounts receivable, net	(612)	(250)
Inventories, net	1,807	(1,131)
Uniforms and other rental items in service	(2,718)	(1,498)
Prepaid expenses and other current assets	(5,419)	(5,939)
Accounts payable	74,361	(17,508)
Accrued compensation and related liabilities	(10,170)	(7,846)
Accrued liabilities and other	(19,352)	(22,306)
Income taxes, current	37,145	39,843
Net cash provided by operating activities	177,313	68,132
Cash flows from investing activities:
Capital expenditures	(30,268)	(26,651)
Proceeds from redemption of marketable securities	0	0
Purchase of marketable securities and investments	(29,496)	(10,148)
Proceeds from Storage transaction		0
Acquisitions of businesses, net of cash acquired	60	0
Other, net	(132,771)	(235,508)
Net cash used in investing activities	(192,475)	(272,307)
Cash flows from financing activities:
Proceeds from issuance of commercial paper, net	0
Proceeds from issuance of debt	(2,000)	(55)
Repayment of debt	0	853
Prepaid short-term debt financing fees	0
Exercise of stock-based compensation awards	0	0
Repurchase of common stock	0	0
Other, net	0	0
Net cash used in financing activities	(2,000)	798
Effect of exchange rate changes on cash and cash equivalents	0	0
Net decrease in cash and cash equivalents	(17,162)	(203,377)
Cash and cash equivalents at beginning of period	55,392	248,716
Cash and cash equivalents at end of period	38,230	45,339
Non- Guarantors
Cash flows from operating activities:
Net income	3,879	2,139
Adjustments to reconcile net income to net cash provided by (used in) operating activities
Depreciation	2,483	2,398
Amortization of intangible assets	207	50
Stock-based compensation	0	0
Gain on Storage transaction		0
Loss on investment in Shred-it Partnership		1,089
Deferred income taxes	(207)	(173)
Change in current assets and liabilities, net of acquisitions of businesses:
Accounts receivable, net	(641)	1,527
Inventories, net	(957)	(334)
Uniforms and other rental items in service	301	(700)
Prepaid expenses and other current assets	(173)	74
Accounts payable	1,022	1,802
Accrued compensation and related liabilities	(1,145)	(1,430)
Accrued liabilities and other	(1,418)	(2,227)
Income taxes, current	234	(102)
Net cash provided by operating activities	3,585	4,113
Cash flows from investing activities:
Capital expenditures	(5,182)	(3,319)
Proceeds from redemption of marketable securities	109,612	152,907
Purchase of marketable securities and investments	(103,805)	(192,097)
Proceeds from Storage transaction		0
Acquisitions of businesses, net of cash acquired	(10,146)	(25,081)
Other, net	1,740	(876)
Net cash used in investing activities	(7,781)	(68,466)
Cash flows from financing activities:
Proceeds from issuance of commercial paper, net	0
Proceeds from issuance of debt	2,000	55
Repayment of debt	0	164
Prepaid short-term debt financing fees	0
Exercise of stock-based compensation awards	0	0
Repurchase of common stock	0	0
Other, net	0	(437)
Net cash used in financing activities	2,000	(218)
Effect of exchange rate changes on cash and cash equivalents	(102)	(1,715)
Net decrease in cash and cash equivalents	(2,298)	(66,286)
Cash and cash equivalents at beginning of period	26,072	93,725
Cash and cash equivalents at end of period	$ 23,774	$ 27,439