Supplemental Guarantor Information (Details 3) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Nov. 30, 2012	Nov. 30, 2011	Nov. 30, 2012	Nov. 30, 2011
Cash flows from operating activities:
Net income	$ 78,027	$ 74,350	$ 154,760	$ 142,988
Adjustments to reconcile net income to net cash provided by (used in) operating activities:
Depreciation			81,321	76,922
Amortization of intangible assets			11,973	20,104
Stock-based compensation			11,084	9,756
Deferred income taxes			55,245	(11,767)
Change in current assets and liabilities, net of acquisitions of businesses:
Accounts receivable, net			(24,528)	(20,850)
Inventories, net			15,460	(39,268)
Uniforms and other rental items in service			(28,105)	(29,630)
Prepaid expenses and other			(202)	(5,128)
Accounts payable			23,019	1,843
Accrued compensation and related liabilities			(36,899)	(15,314)
Accrued liabilities			(36,464)	26,306
Income taxes payable			599	19,996
Net cash provided by operating activities			227,263	175,958
Cash flows from investing activities:
Capital expenditures			(99,062)	(79,832)
Proceeds from redemption of marketable securities			41,453	140,162
Purchase of marketable securities and investments			(80,054)	(193,527)
Acquisitions of businesses, net of cash acquired			(53,243)	(14,551)
Other			(673)	5,772
Net cash used in investing activities			(191,579)	(141,976)
Cash flows from financing activities:
Proceeds from issuance of debt			250,000	0
Repayment of debt			(225,312)	(903)
Exercise of stock-based compensation awards			2,357	78
Repurchase of common stock			(159,175)	(262,682)
Other			(2,476)	1,454
Net cash used in financing activities			(134,606)	(262,053)
Effect of exchange rate changes on cash and cash equivalents			1,584	(2,263)
Net decrease in cash and cash equivalents			(97,338)	(230,334)
Cash and cash equivalents at beginning of period			339,825	438,106
Cash and cash equivalents at end of period	242,487	207,772	242,487	207,772
Cintas Corporation [Member]
Cash flows from operating activities:
Net income	78,027	74,350	154,760	142,988
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			11,084	9,756
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			0	0
Accounts payable			0	0
Accrued compensation and related liabilities			0	0
Accrued liabilities			0	0
Income taxes payable			0	0
Net cash provided by operating activities			165,844	152,744
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
Acquisitions of businesses, net of cash acquired			0	0
Other			(11,749)	109,311
Net cash used in investing activities			(11,749)	109,311
Cash flows from financing activities:
Proceeds from issuance of debt			0
Repayment of debt			0	0
Exercise of stock-based compensation awards			2,357	78
Repurchase of common stock			(159,175)	(262,682)
Other			2,723	549
Net cash used in financing activities			(154,095)	(262,055)
Effect of exchange rate changes on cash and cash equivalents			0	0
Net 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 [Member]
Cash flows from operating activities:
Net income	26,971	31,118	50,563	63,011
Adjustments to reconcile net income to net cash provided by (used in) operating activities:
Depreciation			48,061	47,021
Amortization of intangible assets			10,318	17,305
Stock-based compensation			0	0
Deferred income taxes			(1)	0
Change in current assets and liabilities, net of acquisitions of businesses:
Accounts receivable, net			(20,450)	(14,793)
Inventories, net			9,838	(42,583)
Uniforms and other rental items in service			(15,915)	(22,332)
Prepaid expenses and other			152	(974)
Accounts payable			(41,309)	(51,087)
Accrued compensation and related liabilities			(26,353)	(10,318)
Accrued liabilities			(7,450)	4,485
Income taxes payable			10,815	8,586
Net cash provided by operating activities			18,269	(1,679)
Cash flows from investing activities:
Capital expenditures			(57,660)	(50,166)
Proceeds from redemption of marketable securities			0	0
Purchase of marketable securities and investments			557	(1,282)
Acquisitions of businesses, net of cash acquired			(51,984)	(9,831)
Other			57,625	52,721
Net cash used in investing activities			(51,462)	(8,558)
Cash flows from financing activities:
Proceeds from issuance of debt			250,000
Repayment of debt			(225,542)	(522)
Exercise of stock-based compensation awards			0	0
Repurchase of common stock			0	0
Other			(4,965)	754
Net cash used in financing activities			19,493	232
Effect of exchange rate changes on cash and cash equivalents			(1)	(182)
Net decrease in cash and cash equivalents			(13,701)	(10,187)
Cash and cash equivalents at beginning of period			58,737	54,957
Cash and cash equivalents at end of period	45,036	44,770	45,036	44,770
Subsidiary Guarantors [Member]
Cash flows from operating activities:
Net income	53,226	38,840	103,498	77,548
Adjustments to reconcile net income to net cash provided by (used in) operating activities:
Depreciation			26,608	23,527
Amortization of intangible assets			117	205
Stock-based compensation			0	0
Deferred income taxes			54,959	(12,396)
Change in current assets and liabilities, net of acquisitions of businesses:
Accounts receivable, net			(7,242)	(4,301)
Inventories, net			(2,262)	3,246
Uniforms and other rental items in service			(8,877)	(9,748)
Prepaid expenses and other			(1,170)	(4,476)
Accounts payable			63,503	42,294
Accrued compensation and related liabilities			(9,260)	(4,813)
Accrued liabilities			(27,362)	25,936
Income taxes payable			(8,365)	10,178
Net cash provided by operating activities			184,147	147,200
Cash flows from investing activities:
Capital expenditures			(29,923)	(23,731)
Proceeds from redemption of marketable securities			1,065	0
Purchase of marketable securities and investments			(17,931)	(33,394)
Acquisitions of businesses, net of cash acquired			0	(65)
Other			(201,693)	(268,817)
Net cash used in investing activities			(248,482)	(326,007)
Cash flows from financing activities:
Proceeds from issuance of debt			0
Repayment of debt			1,016	423
Exercise of stock-based compensation awards			0	0
Repurchase of common stock			0	0
Other			0	0
Net cash used in financing activities			1,016	423
Effect of exchange rate changes on cash and cash equivalents			1,485	0
Net decrease in cash and cash equivalents			(61,834)	(178,384)
Cash and cash equivalents at beginning of period			229,287	313,283
Cash and cash equivalents at end of period	167,453	134,899	167,453	134,899
Non-Guarantors [Member]
Cash flows from operating activities:
Net income	2,407	189	5,939	5,061
Adjustments to reconcile net income to net cash provided by (used in) operating activities:
Depreciation			6,652	6,374
Amortization of intangible assets			1,538	2,594
Stock-based compensation			0	0
Deferred income taxes			287	629
Change in current assets and liabilities, net of acquisitions of businesses:
Accounts receivable, net			3,164	(1,756)
Inventories, net			687	790
Uniforms and other rental items in service			(1,244)	(903)
Prepaid expenses and other			816	322
Accounts payable			825	10,636
Accrued compensation and related liabilities			(1,286)	(183)
Accrued liabilities			(2,438)	(4,919)
Income taxes payable			(1,851)	1,232
Net cash provided by operating activities			13,089	19,877
Cash flows from investing activities:
Capital expenditures			(11,479)	(5,935)
Proceeds from redemption of marketable securities			40,388	140,162
Purchase of marketable securities and investments			(64,295)	(189,255)
Acquisitions of businesses, net of cash acquired			(1,259)	(4,655)
Other			1,887	(27)
Net cash used in investing activities			(34,758)	(59,710)
Cash flows from financing activities:
Proceeds from issuance of debt			0
Repayment of debt			0	0
Exercise of stock-based compensation awards			0	0
Repurchase of common stock			0	0
Other			(234)	151
Net cash used in financing activities			(234)	151
Effect of exchange rate changes on cash and cash equivalents			100	(2,081)
Net decrease in cash and cash equivalents			(21,803)	(41,763)
Cash and cash equivalents at beginning of period			51,801	69,866
Cash and cash equivalents at end of period	29,998	28,103	29,998	28,103
Eliminations [Member]
Cash flows from operating activities:
Net income	(82,604)	(70,147)	(160,000)	(145,620)
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
Deferred income taxes			0	0
Change in current assets and liabilities, net of acquisitions of businesses:
Accounts receivable, net			0	0
Inventories, net			7,197	(721)
Uniforms and other rental items in service			(2,069)	3,353
Prepaid expenses and other			0	0
Accounts payable			0	0
Accrued compensation and related liabilities			0	0
Accrued liabilities			786	804
Income taxes payable			0	0
Net cash provided by operating activities			(154,086)	(142,184)
Cash flows from investing activities:
Capital expenditures			0	0
Proceeds from redemption of marketable securities			0	0
Purchase of marketable securities and investments			1,615	30,404
Acquisitions of businesses, net of cash acquired			0	0
Other			153,257	112,584
Net cash used in investing activities			154,872	142,988
Cash flows from financing activities:
Proceeds from issuance of debt			0
Repayment of debt			(786)	(804)
Exercise of stock-based compensation awards			0	0
Repurchase of common stock			0	0
Other			0	0
Net cash used in financing activities			(786)	(804)
Effect of exchange rate changes on cash and cash equivalents			0	0
Net 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