Supplemental Guarantor Information - Condensed Consolidating Statement of Cash Flows (Details) (USD $) In Thousands, unless otherwise specified	6 Months Ended
	Nov. 30, 2014	Nov. 30, 2013
Cash flows from operating activities:
Net income	$ 230,520	$ 162,616
Adjustments to reconcile net income to net cash provided by (used in) operating activities
Depreciation	70,451	85,180
Amortization of intangible assets	7,702	11,741
Stock-based compensation	24,785	14,624
Gain on sale of Storage business	(34,137)	0
Gain on deconsolidation of Shredding business	(6,619)	0
Gain on sale of stock of an equity method investment	(21,739)	0
Deferred income taxes	10,346	9,299
Change in current assets and liabilities, net of acquisitions of businesses:
Accounts receivable, net	(12,747)	(23,755)
Inventories, net	14,847	(9,232)
Uniforms and other rental items in service	(23,473)	(12,694)
Prepaid expenses and other current assets	(2,622)	(1,776)
Accounts payable	27,982	(19,215)
Accrued compensation and related liabilities	(25,111)	(19,381)
Accrued liabilities	24,780	11,387
Income taxes, current	7,608	13,486
Net cash provided by operating activities	292,573	222,280
Cash flows from investing activities:
Capital expenditures	(113,025)	(76,785)
Proceeds from redemption of marketable securities	0	45,114
Purchase of marketable securities and investments	(11,978)	(55,413)
Proceeds from Storage transactions, net of cash contributed	153,996	0
Proceeds from Shredding transaction	3,344	0
Proceeds from sale of stock of an equity method investment	29,933	0
Dividends received on equity method investment	5,247	0
Acquisitions of businesses, net of cash acquired	(3,015)	(32,514)
Other, net	1,681	(929)
Net cash provided by (used in) investing activities	66,183	(120,527)
Cash flows from financing activities:
Proceeds from issuance of debt		0
Repayment of debt	(364)	(7,837)
Exercise of stock-based compensation awards	22,472	21,311
Repurchase of common stock	(63,573)	(164,200)
Other, net	1,758	6,323
Net cash provided by (used in) financing activities	(39,707)	(144,403)
Effect of exchange rate changes on cash and cash equivalents	(5,613)	(289)
Net increase (decrease) in cash and cash equivalents	313,436	(42,939)
Cash and cash equivalents at beginning of period	513,288	352,273
Cash and cash equivalents at end of period	826,724	309,334
Cintas Corporation
Cash flows from operating activities:
Net income	230,520	162,616
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	24,785	14,624
Gain on sale of Storage business	0
Gain on deconsolidation of Shredding business	0
Gain on sale of stock of an equity method investment	0
Deferred income taxes		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	0	0
Income taxes, current	0	0
Net cash provided by operating activities	255,305	177,240
Cash flows from investing activities:
Capital expenditures	0	0
Proceeds from redemption of marketable securities		0
Purchase of marketable securities and investments	0	0
Proceeds from Storage transactions, net of cash contributed	0
Proceeds from Shredding transaction	0
Proceeds from sale of stock of an equity method investment	0
Dividends received on equity method investment	0
Acquisitions of businesses, net of cash acquired	0	0
Other, net	(214,210)	(37,637)
Net cash provided by (used in) investing activities	(214,210)	(37,637)
Cash flows from financing activities:
Proceeds from issuance of debt		0
Repayment of debt	0	0
Exercise of stock-based compensation awards	22,478	21,311
Repurchase of common stock	(63,573)	(164,200)
Other, net	0	3,286
Net cash provided by (used in) financing activities	(41,095)	(139,603)
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
Corp. 2
Cash flows from operating activities:
Net income	79,484	50,953
Adjustments to reconcile net income to net cash provided by (used in) operating activities
Depreciation	38,814	51,331
Amortization of intangible assets	7,251	10,683
Stock-based compensation	0	0
Gain on sale of Storage business	(31,113)
Gain on deconsolidation of Shredding business	(6,619)
Gain on sale of stock of an equity method investment	0
Deferred income taxes	26	0
Change in current assets and liabilities, net of acquisitions of businesses:
Accounts receivable, net	(6,468)	(18,508)
Inventories, net	10,737	(15,354)
Uniforms and other rental items in service	(17,000)	(10,679)
Prepaid expenses and other current assets	327	484
Accounts payable	(144,224)	(27,917)
Accrued compensation and related liabilities	(16,742)	(13,303)
Accrued liabilities	(8,174)	2,366
Income taxes, current	11,945	13,163
Net cash provided by operating activities	(81,756)	43,219
Cash flows from investing activities:
Capital expenditures	(49,870)	(53,379)
Proceeds from redemption of marketable securities		0
Purchase of marketable securities and investments	(2,020)	(1,034)
Proceeds from Storage transactions, net of cash contributed	93,387
Proceeds from Shredding transaction	3,344
Proceeds from sale of stock of an equity method investment	0
Dividends received on equity method investment	0
Acquisitions of businesses, net of cash acquired	(3,015)	(12,364)
Other, net	44,502	45,550
Net cash provided by (used in) investing activities	86,328	(21,227)
Cash flows from financing activities:
Proceeds from issuance of debt		0
Repayment of debt	(634)	(8,086)
Exercise of stock-based compensation awards	0	0
Repurchase of common stock	0	0
Other, net	976	976
Net cash provided by (used in) financing activities	342	(7,110)
Effect of exchange rate changes on cash and cash equivalents	0	0
Net increase (decrease) in cash and cash equivalents	4,914	14,882
Cash and cash equivalents at beginning of period	73,540	54,511
Cash and cash equivalents at end of period	78,454
Subsidiary Guarantors
Cash flows from operating activities:
Net income	143,761	107,679
Adjustments to reconcile net income to net cash provided by (used in) operating activities
Depreciation	25,972	26,590
Amortization of intangible assets	27	83
Stock-based compensation	0	0
Gain on sale of Storage business	0
Gain on deconsolidation of Shredding business	0
Gain on sale of stock of an equity method investment	(21,739)
Deferred income taxes	9,073	9,553
Change in current assets and liabilities, net of acquisitions of businesses:
Accounts receivable, net	(8,938)	(3,886)
Inventories, net	3,258	5,503
Uniforms and other rental items in service	(5,155)	(1,888)
Prepaid expenses and other current assets	(2,943)	(3,146)
Accounts payable	171,596	7,208
Accrued compensation and related liabilities	(6,148)	(5,217)
Accrued liabilities	28,401	10,523
Income taxes, current	(3,814)	1,038
Net cash provided by operating activities	333,351	154,040
Cash flows from investing activities:
Capital expenditures	(57,388)	(17,113)
Proceeds from redemption of marketable securities		5,659
Purchase of marketable securities and investments	55,053	(35,506)
Proceeds from Storage transactions, net of cash contributed	0
Proceeds from Shredding transaction	0
Proceeds from sale of stock of an equity method investment	29,933
Dividends received on equity method investment	5,247
Acquisitions of businesses, net of cash acquired	0	(125)
Other, net	(126,280)	(146,725)
Net cash provided by (used in) investing activities	(93,435)	(193,810)
Cash flows from financing activities:
Proceeds from issuance of debt		2,109
Repayment of debt	1,114	1,024
Exercise of stock-based compensation awards	0	0
Repurchase of common stock	0	0
Other, net	0	0
Net cash provided by (used in) financing activities	1,114	3,133
Effect of exchange rate changes on cash and cash equivalents	0	0
Net increase (decrease) in cash and cash equivalents	241,030	(36,637)
Cash and cash equivalents at beginning of period	399,525	247,070
Cash and cash equivalents at end of period	640,555
Non- Guarantors
Cash flows from operating activities:
Net income	9,814	19,667
Adjustments to reconcile net income to net cash provided by (used in) operating activities
Depreciation	5,665	7,259
Amortization of intangible assets	424	975
Stock-based compensation	0	0
Gain on sale of Storage business	(3,024)
Gain on deconsolidation of Shredding business	0
Gain on sale of stock of an equity method investment	0
Deferred income taxes	1,247	(254)
Change in current assets and liabilities, net of acquisitions of businesses:
Accounts receivable, net	2,659	(1,361)
Inventories, net	(898)	506
Uniforms and other rental items in service	(2,101)	(1,009)
Prepaid expenses and other current assets	(6)	886
Accounts payable	605	1,494
Accrued compensation and related liabilities	(2,221)	(861)
Accrued liabilities	3,807	(2,269)
Income taxes, current	(523)	(715)
Net cash provided by operating activities	15,448	24,318
Cash flows from investing activities:
Capital expenditures	(5,767)	(6,293)
Proceeds from redemption of marketable securities		39,455
Purchase of marketable securities and investments	0	(43,699)
Proceeds from Storage transactions, net of cash contributed	60,609
Proceeds from Shredding transaction	0
Proceeds from sale of stock of an equity method investment	0
Dividends received on equity method investment	0
Acquisitions of businesses, net of cash acquired	0	(20,025)
Other, net	2,137	(14,594)
Net cash provided by (used in) investing activities	56,979	(45,156)
Cash flows from financing activities:
Proceeds from issuance of debt		(2,109)
Repayment of debt	(98)	(8)
Exercise of stock-based compensation awards	(6)	0
Repurchase of common stock	0	0
Other, net	782	2,061
Net cash provided by (used in) financing activities	678	(56)
Effect of exchange rate changes on cash and cash equivalents	(5,613)	(289)
Net increase (decrease) in cash and cash equivalents	67,492	(21,183)
Cash and cash equivalents at beginning of period	40,223	50,692
Cash and cash equivalents at end of period	107,715
Eliminations
Cash flows from operating activities:
Net income	(233,059)	(178,299)
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 Storage business	0
Gain on deconsolidation of Shredding business	0
Gain on sale of stock of an equity method investment	0
Deferred income taxes	0	0
Change in current assets and liabilities, net of acquisitions of businesses:
Accounts receivable, net	0	0
Inventories, net	1,750	113
Uniforms and other rental items in service	783	882
Prepaid expenses and other current assets	0	0
Accounts payable	5	0
Accrued compensation and related liabilities	0	0
Accrued liabilities	746	767
Income taxes, current	0	0
Net cash provided by operating activities	(229,775)	(176,537)
Cash flows from investing activities:
Capital expenditures	0	0
Proceeds from redemption of marketable securities		0
Purchase of marketable securities and investments	(65,011)	24,826
Proceeds from Storage transactions, net of cash contributed	0
Proceeds from Shredding transaction	0
Proceeds from sale of stock of an equity method investment	0
Dividends received on equity method investment	0
Acquisitions of businesses, net of cash acquired	0	0
Other, net	295,532	152,477
Net cash provided by (used in) investing activities	230,521	177,303
Cash flows from financing activities:
Proceeds from issuance of debt		0
Repayment of debt	(746)	(767)
Exercise of stock-based compensation awards	0	0
Repurchase of common stock	0	0
Other, net	0	0
Net cash provided by (used in) financing activities	(746)	(767)
Effect of exchange rate changes on cash and cash equivalents	0	0
Net increase (decrease) in cash and cash equivalents	0	(1)
Cash and cash equivalents at beginning of period	0	0
Cash and cash equivalents at end of period	$ 0