Supplemental Guarantor Information - Consolidating Condensed Statement of Cash Flows (Details) - USD ($) $ in Thousands	3 Months Ended
	Aug. 31, 2017	Aug. 31, 2016
Cash flows from operating activities:
Net income	$ 217,211	$ 138,091
Adjustments to reconcile net income to net cash provided by (used in) operating activities
Depreciation	53,568	39,679
Amortization of intangible assets	14,941	3,489
Stock-based compensation	28,630	20,779
Gain on sale of business	(100,269)
Deferred income taxes	24,938	1,970
Change in current assets and liabilities, net of acquisitions of businesses:
Accounts receivable, net	8,955	(22,946)
Inventories, net	(5,827)	(13,017)
Uniforms and other rental items in service	(13,058)	(1,872)
Prepaid expenses and other current assets	(16,011)	(5,655)
Accounts payable	17,684	17,480
Accrued compensation and related liabilities	(30,306)	(37,276)
Accrued liabilities and other	(16,218)	(23,676)
Income taxes, current	70,128	40,542
Net cash provided by operating activities	254,366	157,588
Cash flows from investing activities:
Capital expenditures	(62,517)	(78,580)
Proceeds from redemption of marketable securities	65,256	109,612
Purchase of marketable securities and investments	(58,022)	(119,729)
Proceeds from sale of business	128,511
Acquisitions of businesses, net of cash acquired	(302)	(10,991)
Other, net	(304)	(918)
Net cash provided by (used in) investing activities	72,622	(100,606)
Cash flows from financing activities:
Payments on commercial paper, net	(43,000)	163,800
Proceeds from issuance of debt		0
Repayment of debt	(250,000)	(250,000)
Prepaid short-term debt financing fees	0	(8,625)
Proceeds from exercise of stock-based compensation awards	17,256	16,282
Repurchase of common stock	(35,040)	(18,870)
Other, net	(649)	385
Net cash used in financing activities	(311,433)	(97,028)
Effect of exchange rate changes on cash and cash equivalents	6,593	(102)
Net (decrease) increase in cash and cash equivalents	22,148	(40,148)
Cash and cash equivalents at beginning of period	169,266	139,357
Cash and cash equivalents at end of period	191,414	99,209
Eliminations
Cash flows from operating activities:
Net income	(214,406)	(135,265)
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 sale of business	0
Deferred income taxes	0	0
Change in current assets and liabilities, net of acquisitions of businesses:
Accounts receivable, net	0	0
Inventories, net	(1,385)	(2,536)
Uniforms and other rental items in service	(279)	(405)
Prepaid expenses and other current assets	0	0
Accounts payable	(153)	115
Accrued compensation and related liabilities	0	0
Accrued liabilities and other	0	0
Income taxes, current	0	0
Net cash provided by operating activities	(216,223)	(138,091)
Cash flows from investing activities:
Capital expenditures	0	0
Proceeds from redemption of marketable securities	0	0
Purchase of marketable securities and investments	2,000	17,733
Proceeds from sale of business	0
Acquisitions of businesses, net of cash acquired	0	0
Other, net	214,223	120,358
Net cash provided by (used in) investing activities	216,223	138,091
Cash flows from financing activities:
Payments on commercial paper, net	0	0
Proceeds from issuance of debt		0
Repayment of debt	0	0
Prepaid short-term debt financing fees		0
Proceeds from 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	0
Effect of exchange rate changes on cash and cash equivalents	0	0
Net (decrease) increase 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	217,211	138,091
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	28,630	20,779
Gain on sale of business	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	245,841	158,870
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 sale of business	0
Acquisitions of businesses, net of cash acquired	0	0
Other, net	(228,057)	(156,282)
Net cash provided by (used in) investing activities	(228,057)	(156,282)
Cash flows from financing activities:
Payments on commercial paper, net	0	0
Proceeds from issuance of debt		0
Repayment of debt	0	0
Prepaid short-term debt financing fees		0
Proceeds from exercise of stock-based compensation awards	17,256	16,282
Repurchase of common stock	(35,040)	(18,870)
Other, net	0	0
Net cash used in financing activities	(17,784)	(2,588)
Effect of exchange rate changes on cash and cash equivalents	0	0
Net (decrease) increase 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	118,530	43,871
Adjustments to reconcile net income to net cash provided by (used in) operating activities
Depreciation	32,658	25,755
Amortization of intangible assets	11,722	3,194
Stock-based compensation	0	0
Gain on sale of business	(115,787)
Deferred income taxes	0	(1,050)
Change in current assets and liabilities, net of acquisitions of businesses:
Accounts receivable, net	(32,847)	(21,693)
Inventories, net	7,262	(11,331)
Uniforms and other rental items in service	(16,077)	950
Prepaid expenses and other current assets	966	(63)
Accounts payable	137,191	(58,018)
Accrued compensation and related liabilities	(15,841)	(25,961)
Accrued liabilities and other	(19,869)	(2,906)
Income taxes, current	20,069	3,163
Net cash provided by operating activities	127,977	(44,089)
Cash flows from investing activities:
Capital expenditures	(36,267)	(43,130)
Proceeds from redemption of marketable securities	12,400	0
Purchase of marketable securities and investments	2,724	(4,161)
Proceeds from sale of business	128,511
Acquisitions of businesses, net of cash acquired	(302)	(905)
Other, net	57,686	166,037
Net cash provided by (used in) investing activities	164,752	117,841
Cash flows from financing activities:
Payments on commercial paper, net	(43,000)	163,800
Proceeds from issuance of debt		0
Repayment of debt	(250,000)	(250,000)
Prepaid short-term debt financing fees		(8,625)
Proceeds from exercise of stock-based compensation awards	0	0
Repurchase of common stock	0	0
Other, net	(478)	385
Net cash used in financing activities	(293,478)	(94,440)
Effect of exchange rate changes on cash and cash equivalents	0	0
Net (decrease) increase in cash and cash equivalents	(749)	(20,688)
Cash and cash equivalents at beginning of period	48,658	57,893
Cash and cash equivalents at end of period	47,909	37,205
Subsidiary Guarantors
Cash flows from operating activities:
Net income	87,171	87,515
Adjustments to reconcile net income to net cash provided by (used in) operating activities
Depreciation	17,613	11,441
Amortization of intangible assets	1,273	88
Stock-based compensation	0	0
Gain on sale of business	15,518
Deferred income taxes	27,468	3,227
Change in current assets and liabilities, net of acquisitions of businesses:
Accounts receivable, net	37,443	(612)
Inventories, net	(11,826)	1,807
Uniforms and other rental items in service	818	(2,718)
Prepaid expenses and other current assets	(17,353)	(5,419)
Accounts payable	(110,445)	74,361
Accrued compensation and related liabilities	(14,403)	(10,170)
Accrued liabilities and other	6,704	(19,352)
Income taxes, current	49,407	37,145
Net cash provided by operating activities	89,388	177,313
Cash flows from investing activities:
Capital expenditures	(31,327)	(30,268)
Proceeds from redemption of marketable securities	0	0
Purchase of marketable securities and investments	(12,223)	(29,496)
Proceeds from sale of business	0
Acquisitions of businesses, net of cash acquired	0	60
Other, net	(23,492)	(132,771)
Net cash provided by (used in) investing activities	(67,042)	(192,475)
Cash flows from financing activities:
Payments on commercial paper, net	0	0
Proceeds from issuance of debt		(2,000)
Repayment of debt	0	0
Prepaid short-term debt financing fees		0
Proceeds from exercise of stock-based compensation awards	0	0
Repurchase of common stock	0	0
Other, net	(171)	0
Net cash used in financing activities	(171)	(2,000)
Effect of exchange rate changes on cash and cash equivalents	0	0
Net (decrease) increase in cash and cash equivalents	22,175	(17,162)
Cash and cash equivalents at beginning of period	17,302	55,392
Cash and cash equivalents at end of period	39,477	38,230
Non- Guarantors
Cash flows from operating activities:
Net income	8,705	3,879
Adjustments to reconcile net income to net cash provided by (used in) operating activities
Depreciation	3,297	2,483
Amortization of intangible assets	1,946	207
Stock-based compensation	0	0
Gain on sale of business	0
Deferred income taxes	(2,530)	(207)
Change in current assets and liabilities, net of acquisitions of businesses:
Accounts receivable, net	4,359	(641)
Inventories, net	122	(957)
Uniforms and other rental items in service	2,480	301
Prepaid expenses and other current assets	376	(173)
Accounts payable	(8,909)	1,022
Accrued compensation and related liabilities	(62)	(1,145)
Accrued liabilities and other	(3,053)	(1,418)
Income taxes, current	652	234
Net cash provided by operating activities	7,383	3,585
Cash flows from investing activities:
Capital expenditures	5,077	(5,182)
Proceeds from redemption of marketable securities	52,856	109,612
Purchase of marketable securities and investments	(50,523)	(103,805)
Proceeds from sale of business	0
Acquisitions of businesses, net of cash acquired	0	(10,146)
Other, net	(20,664)	1,740
Net cash provided by (used in) investing activities	(13,254)	(7,781)
Cash flows from financing activities:
Payments on commercial paper, net	0	0
Proceeds from issuance of debt		2,000
Repayment of debt	0	0
Prepaid short-term debt financing fees		0
Proceeds from 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	2,000
Effect of exchange rate changes on cash and cash equivalents	6,593	(102)
Net (decrease) increase in cash and cash equivalents	722	(2,298)
Cash and cash equivalents at beginning of period	103,306	26,072
Cash and cash equivalents at end of period	$ 104,028	$ 23,774