Supplemental Guarantor Information - Consolidating Condensed Statement of Cash Flows (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Feb. 28, 2017	Feb. 29, 2016	Feb. 28, 2017	Feb. 29, 2016
Cash flows from operating activities:
Net income	$ 118,005	$ 117,341	$ 396,473	$ 562,622
Adjustments to reconcile net income to net cash provided by operating activities
Depreciation			120,493	110,535
Amortization of intangible assets			11,221	12,136
Stock-based compensation			63,578	57,169
Gain on Storage transactions			0	(15,786)
Gain on Shred-it			(25,876)	(349,738)
Deferred income taxes			(3,472)	(74,540)
Change in current assets and liabilities, net of acquisitions of businesses:
Accounts receivable, net			(28,646)	(41,523)
Inventories, net			(23,364)	(24,009)
Uniforms and other rental items in service			(53)	(6,905)
Prepaid expenses and other current assets			(11,387)	(1,580)
Accounts payable			15,538	37,370
Accrued compensation and related liabilities			(5,812)	(3,731)
Accrued liabilities and other			(6,079)	(18,301)
Income taxes, current			(18,856)	53,435
Net cash provided by operating activities			483,758	297,154
Cash flows from investing activities:
Capital expenditures			(218,621)	(207,502)
Proceeds from redemption of marketable securities			172,506	327,779
Purchase of marketable securities and investments			(125,634)	(384,796)
Proceeds from Storage transactions			0	35,338
Proceeds from sale of investment in Shred-it			25,876	578,257
Acquisitions of businesses, net of cash acquired			(19,630)	(151,731)
Other, net			28	4,433
Net cash (used in) provided by investing activities			(165,475)	201,778
Cash flows from financing activities:
Proceeds from issuance of commercial paper, net			99,500	0
Proceeds from issuance of debt			0	0
Repayment of debt			(250,000)	(16)
Prepaid short-term debt financing fees			(13,949)	0
Proceeds from exercise of stock-based compensation awards			25,114	22,260
Dividends paid			(142,444)	(115,273)
Repurchase of common stock			(20,054)	(502,439)
Other, net			(5,801)	1,153
Net cash used in financing activities			(307,634)	(594,315)
Effect of exchange rate changes on cash and cash equivalents			(2,762)	(6,574)
Net increase (decrease) in cash and cash equivalents			7,887	(101,957)
Cash and cash equivalents at beginning of period			139,357	417,073
Cash and cash equivalents at end of period	147,244	315,116	147,244	315,116
Eliminations
Cash flows from operating activities:
Net income	(117,593)	(119,062)	(392,917)	(566,739)
Adjustments to reconcile net income to net cash provided by operating activities
Depreciation			0	0
Amortization of intangible assets			0	0
Stock-based compensation			0	0
Gain on Storage transactions				0
Gain on Shred-it			0	0
Deferred income taxes			0	0
Change in current assets and liabilities, net of acquisitions of businesses:
Accounts receivable, net			0	0
Inventories, net			(1,678)	4,690
Uniforms and other rental items in service			(1,993)	(572)
Prepaid expenses and other current assets			0	0
Accounts payable			114	(1)
Accrued compensation and related liabilities			0	0
Accrued liabilities and other			0	724
Income taxes, current			0	0
Net cash provided by operating activities			(396,474)	(561,898)
Cash flows from investing activities:
Capital expenditures			0	0
Proceeds from redemption of marketable securities			0	0
Purchase of marketable securities and investments			23,608	7,037
Proceeds from Storage transactions				0
Proceeds from sale of investment in Shred-it			0	0
Acquisitions of businesses, net of cash acquired			0	0
Other, net			372,866	555,585
Net cash (used in) provided by investing activities			396,474	562,622
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
Proceeds from exercise of stock-based compensation awards			0	0
Dividends paid			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 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	0	0
Cintas Corporation
Cash flows from operating activities:
Net income	118,005	117,341	396,473	562,622
Adjustments to reconcile net income to net cash provided by operating activities
Depreciation			0	0
Amortization of intangible assets			0	0
Stock-based compensation			63,578	57,169
Gain on Storage transactions				0
Gain on Shred-it			0	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			460,051	619,791
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 transactions				0
Proceeds from sale of investment in Shred-it			0	0
Acquisitions of businesses, net of cash acquired			0	0
Other, net			(322,723)	(24,380)
Net cash (used in) provided by investing activities			(322,723)	(24,380)
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
Proceeds from exercise of stock-based compensation awards			25,114	22,260
Dividends paid			(142,388)	(115,232)
Repurchase of common stock			(20,054)	(502,439)
Other, net			0	0
Net cash used in financing activities			(137,328)	(595,411)
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	0	0
Corp. 2
Cash flows from operating activities:
Net income	37,609	42,285	136,484	347,625
Adjustments to reconcile net income to net cash provided by operating activities
Depreciation			79,459	70,441
Amortization of intangible assets			10,288	11,612
Stock-based compensation			0	0
Gain on Storage transactions				(12,547)
Gain on Shred-it			(23,935)	(362,237)
Deferred income taxes			(11,104)	(82,115)
Change in current assets and liabilities, net of acquisitions of businesses:
Accounts receivable, net			(21,965)	(29,955)
Inventories, net			(21,588)	(25,169)
Uniforms and other rental items in service			3,662	(2,339)
Prepaid expenses and other current assets			(6,460)	55
Accounts payable			(36,312)	(358,602)
Accrued compensation and related liabilities			(3,243)	(2,373)
Accrued liabilities and other			(10,958)	(21,747)
Income taxes, current			10,886	55,609
Net cash provided by operating activities			105,214	(411,742)
Cash flows from investing activities:
Capital expenditures			(125,995)	(120,943)
Proceeds from redemption of marketable securities			0	0
Purchase of marketable securities and investments			(5,644)	(3,838)
Proceeds from Storage transactions				32,099
Proceeds from sale of investment in Shred-it			23,935	565,643
Acquisitions of businesses, net of cash acquired			(9,097)	(127,524)
Other, net			166,718	121,547
Net cash (used in) provided by investing activities			49,917	466,984
Cash flows from financing activities:
Proceeds from issuance of commercial paper, net			99,500
Proceeds from issuance of debt			0	0
Repayment of debt			(250,000)	(309)
Prepaid short-term debt financing fees			(13,949)
Proceeds from exercise of stock-based compensation awards			0	0
Dividends paid			0	0
Repurchase of common stock			0	0
Other, net			(5,801)	1,464
Net cash used in financing activities			(170,250)	1,155
Effect of exchange rate changes on cash and cash equivalents			0	0
Net increase (decrease) in cash and cash equivalents			(15,119)	56,397
Cash and cash equivalents at beginning of period			57,893	74,632
Cash and cash equivalents at end of period	42,774	131,029	42,774	131,029
Subsidiary Guarantors
Cash flows from operating activities:
Net income	78,059	75,058	244,759	219,644
Adjustments to reconcile net income to net cash provided by operating activities
Depreciation			33,697	33,208
Amortization of intangible assets			262	218
Stock-based compensation			0	0
Gain on Storage transactions				0
Gain on Shred-it			0	0
Deferred income taxes			7,406	5,895
Change in current assets and liabilities, net of acquisitions of businesses:
Accounts receivable, net			(5,959)	(11,251)
Inventories, net			2,079	(1,584)
Uniforms and other rental items in service			(2,753)	(1,876)
Prepaid expenses and other current assets			(5,037)	(1,730)
Accounts payable			45,593	385,841
Accrued compensation and related liabilities			(3,099)	(1,118)
Accrued liabilities and other			5,110	4,233
Income taxes, current			(29,632)	(2,042)
Net cash provided by operating activities			292,426	629,438
Cash flows from investing activities:
Capital expenditures			(77,025)	(76,161)
Proceeds from redemption of marketable securities			0	0
Purchase of marketable securities and investments			(41,180)	(2,235)
Proceeds from Storage transactions				0
Proceeds from sale of investment in Shred-it			0	0
Acquisitions of businesses, net of cash acquired			0	0
Other, net			(218,390)	(649,264)
Net cash (used in) provided by investing activities			(336,595)	(727,660)
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	1,053
Prepaid short-term debt financing fees			0
Proceeds from exercise of stock-based compensation awards			0	0
Dividends paid			0	0
Repurchase of common stock			0	0
Other, net			0	0
Net cash used in financing activities			(2,000)	998
Effect of exchange rate changes on cash and cash equivalents			0	0
Net increase (decrease) in cash and cash equivalents			(46,169)	(97,224)
Cash and cash equivalents at beginning of period			55,392	248,716
Cash and cash equivalents at end of period	9,223	151,492	9,223	151,492
Non- Guarantors
Cash flows from operating activities:
Net income	1,925	1,719	11,674	(530)
Adjustments to reconcile net income to net cash provided by operating activities
Depreciation			7,337	6,886
Amortization of intangible assets			671	306
Stock-based compensation			0	0
Gain on Storage transactions				(3,239)
Gain on Shred-it			(1,941)	12,499
Deferred income taxes			226	1,680
Change in current assets and liabilities, net of acquisitions of businesses:
Accounts receivable, net			(722)	(317)
Inventories, net			(2,177)	(1,946)
Uniforms and other rental items in service			1,031	(2,118)
Prepaid expenses and other current assets			110	95
Accounts payable			6,143	10,132
Accrued compensation and related liabilities			530	(240)
Accrued liabilities and other			(231)	(1,511)
Income taxes, current			(110)	(132)
Net cash provided by operating activities			22,541	21,565
Cash flows from investing activities:
Capital expenditures			(15,601)	(10,398)
Proceeds from redemption of marketable securities			172,506	327,779
Purchase of marketable securities and investments			(102,418)	(385,760)
Proceeds from Storage transactions				3,239
Proceeds from sale of investment in Shred-it			1,941	12,614
Acquisitions of businesses, net of cash acquired			(10,533)	(24,207)
Other, net			1,557	945
Net cash (used in) provided by investing activities			47,452	(75,788)
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	(36)
Prepaid short-term debt financing fees			0
Proceeds from exercise of stock-based compensation awards			0	0
Dividends paid			(56)	(41)
Repurchase of common stock			0	0
Other, net			0	(311)
Net cash used in financing activities			1,944	(333)
Effect of exchange rate changes on cash and cash equivalents			(2,762)	(6,574)
Net increase (decrease) in cash and cash equivalents			69,175	(61,130)
Cash and cash equivalents at beginning of period			26,072	93,725
Cash and cash equivalents at end of period	$ 95,247	$ 32,595	$ 95,247	$ 32,595