Supplemental Guarantor Information - Consolidating Condensed Statement of Cash Flows (Details) - USD ($) $ in Thousands	3 Months Ended
	Aug. 31, 2018	Aug. 31, 2017
Cash flows from operating activities:
Net income	$ 212,515	$ 217,211
Adjustments to reconcile net income to net cash provided by operating activities
Depreciation	52,745	53,568
Amortization of intangible assets and capitalized contract costs	33,550	14,941
Stock-based compensation	46,172	28,630
(Gain) loss on sale of business		(100,269)
Deferred income taxes	9,022	24,938
Change in current assets and liabilities, net of acquisitions of businesses:
Accounts receivable, net	(15,051)	8,955
Inventories, net	(34,629)	(5,827)
Uniforms and other rental items in service	(23,019)	(13,058)
Prepaid expenses and other current assets and other assets, net	(46,930)	(16,011)
Accounts payable	(329)	17,684
Accrued compensation and related liabilities	(56,186)	(30,306)
Accrued liabilities and other	(27,556)	(16,218)
Income taxes, current	12,681	70,128
Net cash provided by operating activities	162,985	254,366
Cash flows from investing activities:
Capital expenditures	(64,528)	(62,517)
Proceeds from redemption of marketable securities	1,558	65,256
Purchase of marketable securities and investments	0	(58,022)
Proceeds from sale of business	0	128,511
Acquisitions of businesses, net of cash acquired	(7,613)	(302)
Other, net	(202)	(304)
Net cash (used in) provided by investing activities	(70,785)	72,622
Cash flows from financing activities:
Payments of commercial paper, net	0	(43,000)
Repayment of debt	0	(250,000)
Proceeds from exercise of stock-based compensation awards	27,512	17,256
Repurchase of common stock	(139,468)	(35,040)
Other, net	(552)	(649)
Net cash used in financing activities	(112,508)	(311,433)
Effect of exchange rate changes on cash and cash equivalents	(60)	6,593
Net increase (decrease) in cash and cash equivalents	(20,368)	22,148
Cash and cash equivalents at beginning of period	138,724	169,266
Cash and cash equivalents at end of period	118,356	191,414
Eliminations
Cash flows from operating activities:
Net income	(210,655)	(214,406)
Adjustments to reconcile net income to net cash provided by operating activities
Depreciation	0	0
Amortization of intangible assets and capitalized contract costs	0	0
Stock-based compensation	0	0
(Gain) loss 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	(782)	(1,385)
Uniforms and other rental items in service	(1,379)	(279)
Prepaid expenses and other current assets and other assets, net	0	0
Accounts payable	302	(153)
Accrued compensation and related liabilities	0	0
Accrued liabilities and other	0	0
Income taxes, current	0	0
Net cash provided by operating activities	(212,514)	(216,223)
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
Proceeds from sale of business		0
Acquisitions of businesses, net of cash acquired	0	0
Other, net	213,504	214,223
Net cash (used in) provided by investing activities	213,504	216,223
Cash flows from financing activities:
Payments of commercial paper, net		0
Repayment of debt		0
Proceeds from exercise of stock-based compensation awards	0	0
Repurchase of common stock	0	0
Other, net	(990)	0
Net cash used in financing activities	(990)	0
Effect of exchange rate changes on cash and cash equivalents	0	0
Net increase (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	212,515	217,211
Adjustments to reconcile net income to net cash provided by operating activities
Depreciation	0	0
Amortization of intangible assets and capitalized contract costs	0	0
Stock-based compensation	46,172	28,630
(Gain) loss 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 and other assets, net	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	258,687	245,841
Cash flows from investing activities:
Capital expenditures	0	0
Proceeds from redemption of marketable securities	0	0
Purchase of marketable securities and investments		0
Proceeds from sale of business		0
Acquisitions of businesses, net of cash acquired	0	0
Other, net	(146,731)	(228,057)
Net cash (used in) provided by investing activities	(146,731)	(228,057)
Cash flows from financing activities:
Payments of commercial paper, net		0
Repayment of debt		0
Proceeds from exercise of stock-based compensation awards	27,512	17,256
Repurchase of common stock	(139,468)	(35,040)
Other, net	0	0
Net cash used in financing activities	(111,956)	(17,784)
Effect of exchange rate changes on cash and cash equivalents	0	0
Net increase (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	62,612	118,530
Adjustments to reconcile net income to net cash provided by operating activities
Depreciation	33,866	32,658
Amortization of intangible assets and capitalized contract costs	30,156	11,722
Stock-based compensation	0	0
(Gain) loss on sale of business		(115,787)
Deferred income taxes	5,388	0
Change in current assets and liabilities, net of acquisitions of businesses:
Accounts receivable, net	(12,891)	(32,847)
Inventories, net	(37,207)	7,262
Uniforms and other rental items in service	(10,800)	(16,077)
Prepaid expenses and other current assets and other assets, net	(25,060)	966
Accounts payable	41,784	137,191
Accrued compensation and related liabilities	(41,910)	(15,841)
Accrued liabilities and other	2,305	(19,869)
Income taxes, current	5,022	20,069
Net cash provided by operating activities	53,265	127,977
Cash flows from investing activities:
Capital expenditures	(43,966)	(36,267)
Proceeds from redemption of marketable securities	1,554	12,400
Purchase of marketable securities and investments		2,724
Proceeds from sale of business		128,511
Acquisitions of businesses, net of cash acquired	(7,613)	(302)
Other, net	(4,048)	57,686
Net cash (used in) provided by investing activities	(54,073)	164,752
Cash flows from financing activities:
Payments of commercial paper, net		(43,000)
Repayment of debt		(250,000)
Proceeds from exercise of stock-based compensation awards	0	0
Repurchase of common stock	0	0
Other, net	2,909	(478)
Net cash used in financing activities	2,909	(293,478)
Effect of exchange rate changes on cash and cash equivalents	0	0
Net increase (decrease) in cash and cash equivalents	2,101	(749)
Cash and cash equivalents at beginning of period	44,499	48,658
Cash and cash equivalents at end of period	46,600	47,909
Subsidiary Guarantors
Cash flows from operating activities:
Net income	143,033	87,171
Adjustments to reconcile net income to net cash provided by operating activities
Depreciation	15,427	17,613
Amortization of intangible assets and capitalized contract costs	1,278	1,273
Stock-based compensation	0	0
(Gain) loss on sale of business		15,518
Deferred income taxes	2,122	27,468
Change in current assets and liabilities, net of acquisitions of businesses:
Accounts receivable, net	3,381	37,443
Inventories, net	2,700	(11,826)
Uniforms and other rental items in service	(7,904)	818
Prepaid expenses and other current assets and other assets, net	(21,838)	(17,353)
Accounts payable	(37,657)	(110,445)
Accrued compensation and related liabilities	(10,982)	(14,403)
Accrued liabilities and other	(26,295)	6,704
Income taxes, current	8,474	49,407
Net cash provided by operating activities	71,739	89,388
Cash flows from investing activities:
Capital expenditures	(17,979)	(31,327)
Proceeds from redemption of marketable securities	4	0
Purchase of marketable securities and investments		(12,223)
Proceeds from sale of business		0
Acquisitions of businesses, net of cash acquired	0	0
Other, net	(65,509)	(23,492)
Net cash (used in) provided by investing activities	(83,484)	(67,042)
Cash flows from financing activities:
Payments of commercial paper, net		0
Repayment of debt		0
Proceeds from exercise of stock-based compensation awards	0	0
Repurchase of common stock	0	0
Other, net	0	(171)
Net cash used in financing activities	0	(171)
Effect of exchange rate changes on cash and cash equivalents	0	0
Net increase (decrease) in cash and cash equivalents	(11,745)	22,175
Cash and cash equivalents at beginning of period	60,310	17,302
Cash and cash equivalents at end of period	48,565	39,477
Non- Guarantors
Cash flows from operating activities:
Net income	5,010	8,705
Adjustments to reconcile net income to net cash provided by operating activities
Depreciation	3,452	3,297
Amortization of intangible assets and capitalized contract costs	2,116	1,946
Stock-based compensation	0	0
(Gain) loss on sale of business		0
Deferred income taxes	1,512	(2,530)
Change in current assets and liabilities, net of acquisitions of businesses:
Accounts receivable, net	(5,541)	4,359
Inventories, net	660	122
Uniforms and other rental items in service	(2,936)	2,480
Prepaid expenses and other current assets and other assets, net	(32)	376
Accounts payable	(4,758)	(8,909)
Accrued compensation and related liabilities	(3,294)	(62)
Accrued liabilities and other	(3,566)	(3,053)
Income taxes, current	(815)	652
Net cash provided by operating activities	(8,192)	7,383
Cash flows from investing activities:
Capital expenditures	(2,583)	5,077
Proceeds from redemption of marketable securities	0	52,856
Purchase of marketable securities and investments		(50,523)
Proceeds from sale of business		0
Acquisitions of businesses, net of cash acquired	0	0
Other, net	2,582	(20,664)
Net cash (used in) provided by investing activities	(1)	(13,254)
Cash flows from financing activities:
Payments of commercial paper, net		0
Repayment of debt		0
Proceeds from exercise of stock-based compensation awards	0	0
Repurchase of common stock	0	0
Other, net	(2,471)	0
Net cash used in financing activities	(2,471)	0
Effect of exchange rate changes on cash and cash equivalents	(60)	6,593
Net increase (decrease) in cash and cash equivalents	(10,724)	722
Cash and cash equivalents at beginning of period	33,915	103,306
Cash and cash equivalents at end of period	$ 23,191	$ 104,028