Supplemental Guarantor Information (Condensed Consolidating Statement of Cash Flows) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Aug. 31, 2014	Aug. 31, 2013
Cash flows from operating activities:
Net income	$ 110,108	$ 77,754
Adjustments to reconcile net income to net cash provided by (used in) operating activities
Depreciation	35,448	42,571
Amortization of intangible assets	4,206	5,823
Stock-based compensation	12,280	6,984
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	2,108	7,373
Change in current assets and liabilities, net of acquisitions of businesses:
Accounts receivable, net	8,222	(14,903)
Inventories, net	1,377	(5,258)
Uniforms and other rental items in service	(7,112)	(4,150)
Prepaid expenses and other current assets	(5,884)	(7,216)
Accounts payable	(1,325)	2,915
Accrued compensation and related liabilities	(41,262)	(34,777)
Accrued liabilities	10,384	(27,215)
Income taxes, current	48,009	32,658
Net cash provided by operating activities	148,201	82,559
Cash flows from investing activities:
Capital expenditures	(68,050)	(37,462)
Proceeds from redemption of marketable securities	0	35,233
Purchase of marketable securities and investments	(6,981)	(32,941)
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	(2,328)	(32,216)
Other, net	16	382
Net cash used in investing activities	(38,819)	(67,004)
Cash flows from financing activities:
Proceeds from issuance of debt		0
Repayment of debt	(180)	(167)
Exercise of stock-based compensation awards	13,623	14,085
Repurchase of common stock	(61,439)	(106,977)
Other, net	6,798	4,126
Net cash used in financing activities	(41,198)	(88,933)
Effect of exchange rate changes on cash and cash equivalents	(19)	(225)
Net increase (decrease) in cash and cash equivalents	68,165	(73,603)
Cash and cash equivalents at beginning of period	513,288	352,273
Cash and cash equivalents at end of period	581,453	278,670
Cintas Corporation
Cash flows from operating activities:
Net income	110,108	77,754
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	12,280	6,984
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	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	122,388	84,738
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 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	(80,725)	5,309
Net cash used in investing activities	(80,725)	5,309
Cash flows from financing activities:
Proceeds from issuance of debt		0
Repayment of debt	0	0
Exercise of stock-based compensation awards	13,623	14,085
Repurchase of common stock	(61,439)	(106,977)
Other, net	6,153	2,845
Net cash used in financing activities	(41,663)	(90,047)
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	33,150	25,681
Adjustments to reconcile net income to net cash provided by (used in) operating activities
Depreciation	19,547	25,690
Amortization of intangible assets	3,773	5,318
Stock-based compensation	0	0
Gain on deconsolidation of Shredding business	(6,619)
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	10,014	(9,495)
Inventories, net	(1,045)	(8,071)
Uniforms and other rental items in service	(4,450)	(4,274)
Prepaid expenses and other current assets	200	(81)
Accounts payable	(70,520)	(1,001)
Accrued compensation and related liabilities	(28,267)	(24,197)
Accrued liabilities	(31,741)	(13,567)
Income taxes, current	6,913	5,897
Net cash provided by operating activities	(69,045)	1,900
Cash flows from investing activities:
Capital expenditures	(22,686)	(25,556)
Proceeds from redemption of marketable securities		0
Purchase of marketable securities and investments	(1,721)	(67)
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	(2,328)	(12,306)
Other, net	94,602	45,815
Net cash used in investing activities	71,211	7,886
Cash flows from financing activities:
Proceeds from issuance of debt		0
Repayment of debt	(450)	(416)
Exercise of stock-based compensation awards	0	0
Repurchase of common stock	0	0
Other, net	488	488
Net cash used in financing activities	38	72
Effect of exchange rate changes on cash and cash equivalents	0	0
Net increase (decrease) in cash and cash equivalents	2,204	9,858
Cash and cash equivalents at beginning of period	73,540	54,511
Cash and cash equivalents at end of period	75,744	64,369
Subsidiary Guarantors
Cash flows from operating activities:
Net income	75,016	50,957
Adjustments to reconcile net income to net cash provided by (used in) operating activities
Depreciation	13,037	13,305
Amortization of intangible assets	15	41
Stock-based compensation	0	0
Gain on deconsolidation of Shredding business	0
Gain on sale of stock of an equity method investment	(21,739)
Deferred income taxes	2,083	7,735
Change in current assets and liabilities, net of acquisitions of businesses:
Accounts receivable, net	(3,852)	(5,449)
Inventories, net	2,430	2,675
Uniforms and other rental items in service	(1,673)	(842)
Prepaid expenses and other current assets	(6,288)	(7,416)
Accounts payable	71,606	4,147
Accrued compensation and related liabilities	(10,204)	(8,765)
Accrued liabilities	42,084	(11,060)
Income taxes, current	40,601	27,252
Net cash provided by operating activities	203,116	72,580
Cash flows from investing activities:
Capital expenditures	(42,239)	(8,804)
Proceeds from redemption of marketable securities		5,659
Purchase of marketable securities and investments	(15,260)	(23,946)
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	(1)
Other, net	(114,793)	(103,631)
Net cash used in investing activities	(137,112)	(130,723)
Cash flows from financing activities:
Proceeds from issuance of debt		953
Repayment of debt	1,116	1,016
Exercise of stock-based compensation awards	0	0
Repurchase of common stock	0	0
Other, net	0	0
Net cash used in financing activities	1,116	1,969
Effect of exchange rate changes on cash and cash equivalents	0	0
Net increase (decrease) in cash and cash equivalents	67,120	(56,174)
Cash and cash equivalents at beginning of period	399,525	247,070
Cash and cash equivalents at end of period	466,645	190,896
Non-Guarantors
Cash flows from operating activities:
Net income	3,177	16,394
Adjustments to reconcile net income to net cash provided by (used in) operating activities
Depreciation	2,864	3,576
Amortization of intangible assets	418	464
Stock-based compensation	0	0
Gain on deconsolidation of Shredding business	0
Gain on sale of stock of an equity method investment	0
Deferred income taxes	25	(362)
Change in current assets and liabilities, net of acquisitions of businesses:
Accounts receivable, net	2,060	41
Inventories, net	(1,174)	426
Uniforms and other rental items in service	(1,053)	87
Prepaid expenses and other current assets	204	281
Accounts payable	(2,415)	(231)
Accrued compensation and related liabilities	(2,791)	(1,815)
Accrued liabilities	(705)	(3,355)
Income taxes, current	495	(491)
Net cash provided by operating activities	1,105	15,015
Cash flows from investing activities:
Capital expenditures	(3,125)	(3,102)
Proceeds from redemption of marketable securities		29,574
Purchase of marketable securities and investments	0	(33,818)
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	(19,909)
Other, net	823	(14,662)
Net cash used in investing activities	(2,302)	(41,917)
Cash flows from financing activities:
Proceeds from issuance of debt		(953)
Repayment of debt	(100)	0
Exercise of stock-based compensation awards	0	0
Repurchase of common stock	0	0
Other, net	157	793
Net cash used in financing activities	57	(160)
Effect of exchange rate changes on cash and cash equivalents	(19)	(225)
Net increase (decrease) in cash and cash equivalents	(1,159)	(27,287)
Cash and cash equivalents at beginning of period	40,223	50,692
Cash and cash equivalents at end of period	39,064	23,405
Eliminations
Cash flows from operating activities:
Net income	(111,343)	(93,032)
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 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	1,166	(288)
Uniforms and other rental items in service	64	879
Prepaid expenses and other current assets	0	0
Accounts payable	4	0
Accrued compensation and related liabilities	0	0
Accrued liabilities	746	767
Income taxes, current	0	0
Net cash provided by operating activities	(109,363)	(91,674)
Cash flows from investing activities:
Capital expenditures	0	0
Proceeds from redemption of marketable securities		0
Purchase of marketable securities and investments	10,000	24,890
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	100,109	67,551
Net cash used in investing activities	110,109	92,441
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 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	0
Cash and cash equivalents at beginning of period	0	0
Cash and cash equivalents at end of period	$ 0	$ 0