Supplemental Guarantor Information (Condensed Consolidating Statement of Cash Flows) (Details) (USD $)	12 Months Ended
	May 31, 2013	May 31, 2012	May 31, 2011
Cash flows from operating activities:
Net income	$ 315,442,000	$ 297,637,000	$ 246,989,000
Adjustments to reconcile net income to net cash provided by (used in) operating activities:
Depreciation	165,664,000	155,831,000	150,886,000
Amortization of intangible assets	23,713,000	38,334,000	42,581,000
Stock-based compensation	23,310,000	20,312,000	15,203,000
Deferred income taxes	48,023,000	56,727,000	47,908,000
Change in current assets and liabilities, net of acquisitions of businesses:
Accounts receivable, net	(42,704,000)	(24,261,000)	(48,986,000)
Inventories, net	10,997,000	(2,330,000)	(78,824,000)
Uniforms and other rental items in service	(44,179,000)	(60,279,000)	(58,180,000)
Prepaid expenses	(3,281,000)	(1,496,000)	360,000
Accounts payable	25,023,000	(12,557,000)	29,215,000
Accrued compensation and related liabilities	(13,161,000)	11,625,000	12,493,000
Accrued liabilities	31,873,000	(20,371,000)	(2,167,000)
Income taxes, current	12,028,000	10,690,000	(16,592,000)
Net cash provided by operating activities	552,748,000	469,862,000	340,886,000
Cash flows from investing activities:
Capital expenditures	(196,486,000)	(160,802,000)	(182,592,000)
Proceeds from redemption of marketable securities	161,478,000	665,016,000	139,056,000
Purchase of marketable securities and investments	(178,464,000)	(585,655,000)	(78,307,000)
Acquisitions of businesses, net of cash acquired	(69,370,000)	(24,864,000)	(171,552,000)
Other	(1,339,000)	2,011,000	(5,198,000)
Net cash used in investing activities	(284,181,000)	(104,294,000)	(298,593,000)
Cash flows from financing activities:
Proceeds from issuance of debt	250,000,000	0	1,002,281,000
Repayment of debt	(225,636,000)	(1,323,000)	(502,208,000)
Proceeds from exercise of stock-based compensation awards	14,807,000	3,341,000	0
Dividends paid	(79,744,000)	(70,820,000)	(71,812,000)
Repurchase of common stock	(215,681,000)	(392,328,000)	(443,690,000)
Other	196,000	555,000	(4,609,000)
Net cash used in financing activities	(256,058,000)	(460,575,000)	(20,038,000)
Effect of exchange rate changes on cash and cash equivalents	(61,000)	(3,274,000)	4,570,000
Net increase (decrease) in cash and cash equivalents	12,448,000	(98,281,000)	26,825,000
Cash and cash equivalents at beginning of year	339,825,000	438,106,000	411,281,000
Cash and cash equivalents at end of year	352,273,000	339,825,000	438,106,000
Cintas Corporation [Member]
Cash flows from operating activities:
Net income	315,442,000	297,637,000	246,989,000
Adjustments to reconcile net income to net cash provided by (used in) operating activities:
Depreciation	0	0	0
Amortization of intangible assets	0	0	0
Stock-based compensation	23,310,000	20,312,000	15,203,000
Deferred income taxes	0	0	0
Change in current assets and liabilities, net of acquisitions of businesses:
Accounts receivable, net	0	0	0
Inventories, net	0	0	0
Uniforms and other rental items in service	0	0	0
Prepaid expenses	0	0	0
Accounts payable	0	0	0
Accrued compensation and related liabilities	0	0	0
Accrued liabilities	0	0	0
Income taxes, current	0	0	0
Net cash provided by operating activities	338,752,000	317,949,000	262,192,000
Cash flows from investing activities:
Capital expenditures	0	0	0
Proceeds from redemption of marketable securities	0	0	0
Purchase of marketable securities and investments	0	0	0
Acquisitions of businesses, net of cash acquired	0	0	0
Other	(60,918,000)	141,350,000	253,387,000
Net cash used in investing activities	(60,918,000)	141,350,000	253,387,000
Cash flows from financing activities:
Proceeds from issuance of debt	0	0	0
Repayment of debt	0	0	0
Proceeds from exercise of stock-based compensation awards	14,807,000	3,341,000
Dividends paid	(79,723,000)	(70,800,000)	(71,801,000)
Repurchase of common stock	(215,681,000)	(392,328,000)	(443,690,000)
Other	2,763,000	488,000	(88,000)
Net cash used in financing activities	(277,834,000)	(459,299,000)	(515,579,000)
Effect of exchange rate changes on cash and cash equivalents	0	0	0
Net increase (decrease) in cash and cash equivalents	0	0	0
Cash and cash equivalents at beginning of year	0	0	0
Cash and cash equivalents at end of year	0	0	0
Corp. 2 [Member]
Cash flows from operating activities:
Net income	98,748,000	165,559,000	105,914,000
Adjustments to reconcile net income to net cash provided by (used in) operating activities:
Depreciation	16,647,000	102,613,000	103,039,000
Amortization of intangible assets	21,077,000	33,114,000	37,615,000
Stock-based compensation	0	0	0
Deferred income taxes	0	0	(4,886,000)
Change in current assets and liabilities, net of acquisitions of businesses:
Accounts receivable, net	(25,206,000)	(15,280,000)	(39,060,000)
Inventories, net	9,034,000	(5,635,000)	(59,223,000)
Uniforms and other rental items in service	(26,364,000)	(34,401,000)	(45,149,000)
Prepaid expenses	507,000	(2,154,000)	223,000
Accounts payable	(55,802,000)	(143,189,000)	(392,210,000)
Accrued compensation and related liabilities	(9,206,000)	8,659,000	12,957,000
Accrued liabilities	(5,416,000)	16,929,000	(2,740,000)
Income taxes, current	1,110,000	(4,357,000)	4,265,000
Net cash provided by operating activities	25,129,000	121,858,000	(279,255,000)
Cash flows from investing activities:
Capital expenditures	(39,975,000)	(116,954,000)	(99,739,000)
Proceeds from redemption of marketable securities	0	0	0
Purchase of marketable securities and investments	(683,000)	(2,740,000)	(16,897,000)
Acquisitions of businesses, net of cash acquired	(67,431,000)	(19,323,000)	(133,378,000)
Other	58,589,000	20,090,000	54,296,000
Net cash used in investing activities	(49,500,000)	(118,927,000)	(195,718,000)
Cash flows from financing activities:
Proceeds from issuance of debt	250,000,000	0	1,000,500,000
Repayment of debt	(225,866,000)	(843,000)	(501,316,000)
Proceeds from exercise of stock-based compensation awards	0	0
Dividends paid	0	0	0
Repurchase of common stock	0	0	0
Other	(3,989,000)	1,508,000	(4,576,000)
Net cash used in financing activities	20,145,000	665,000	494,608,000
Effect of exchange rate changes on cash and cash equivalents	0	184,000	417,000
Net increase (decrease) in cash and cash equivalents	(4,226,000)	3,780,000	20,052,000
Cash and cash equivalents at beginning of year	58,737,000	54,957,000	34,905,000
Cash and cash equivalents at end of year	54,511,000	58,737,000	54,957,000
Subsidiary Guarantors [Member]
Cash flows from operating activities:
Net income	216,727,000	230,677,000	134,424,000
Adjustments to reconcile net income to net cash provided by (used in) operating activities:
Depreciation	135,345,000	40,613,000	36,032,000
Amortization of intangible assets	200,000	393,000	543,000
Stock-based compensation	0	0	0
Deferred income taxes	53,916,000	56,411,000	51,996,000
Change in current assets and liabilities, net of acquisitions of businesses:
Accounts receivable, net	(15,326,000)	(4,985,000)	(2,079,000)
Inventories, net	(5,292,000)	4,685,000	(8,112,000)
Uniforms and other rental items in service	(11,590,000)	(19,286,000)	(11,671,000)
Prepaid expenses	(3,620,000)	950,000	2,085,000
Accounts payable	75,034,000	661,243,000	393,185,000
Accrued compensation and related liabilities	(3,977,000)	1,466,000	(1,577,000)
Accrued liabilities	38,099,000	(30,586,000)	(6,318,000)
Income taxes, current	206,000	4,712,000	(8,858,000)
Net cash provided by operating activities	479,722,000	946,293,000	579,650,000
Cash flows from investing activities:
Capital expenditures	(131,208,000)	(26,270,000)	(68,274,000)
Proceeds from redemption of marketable securities	13,899,000	0	23,206,000
Purchase of marketable securities and investments	(31,075,000)	(416,100,000)	(55,438,000)
Acquisitions of businesses, net of cash acquired	112,000	(65,000)	(1,831,000)
Other	(315,519,000)	(588,518,000)	(504,637,000)
Net cash used in investing activities	(463,791,000)	(1,030,953,000)	(606,974,000)
Cash flows from financing activities:
Proceeds from issuance of debt	638,000	(786,000)	1,781,000
Repayment of debt	445,000	324,000	(876,000)
Proceeds from exercise of stock-based compensation awards	0	0
Dividends paid	0	0	0
Repurchase of common stock	0	0	0
Other	769,000	(574,000)	0
Net cash used in financing activities	1,852,000	(1,036,000)	905,000
Effect of exchange rate changes on cash and cash equivalents	0	1,700,000	0
Net increase (decrease) in cash and cash equivalents	17,783,000	(83,996,000)	(26,419,000)
Cash and cash equivalents at beginning of year	229,287,000	313,283,000	339,702,000
Cash and cash equivalents at end of year	247,070,000	229,287,000	313,283,000
Non-Guarantors [Member]
Cash flows from operating activities:
Net income	32,793,000	437,579,000	103,964,000
Adjustments to reconcile net income to net cash provided by (used in) operating activities:
Depreciation	13,672,000	12,605,000	11,815,000
Amortization of intangible assets	2,436,000	4,827,000	4,423,000
Stock-based compensation	0	0	0
Deferred income taxes	(5,893,000)	316,000	798,000
Change in current assets and liabilities, net of acquisitions of businesses:
Accounts receivable, net	(2,172,000)	(3,996,000)	(7,847,000)
Inventories, net	626,000	1,590,000	(2,957,000)
Uniforms and other rental items in service	(4,077,000)	(1,477,000)	(7,179,000)
Prepaid expenses	(168,000)	(292,000)	(1,948,000)
Accounts payable	5,794,000	(530,611,000)	28,244,000
Accrued compensation and related liabilities	22,000	1,500,000	1,113,000
Accrued liabilities	(829,000)	(6,732,000)	6,875,000
Income taxes, current	10,712,000	10,335,000	(11,999,000)
Net cash provided by operating activities	52,916,000	(74,356,000)	125,302,000
Cash flows from investing activities:
Capital expenditures	(25,303,000)	(17,578,000)	(14,579,000)
Proceeds from redemption of marketable securities	147,579,000	665,016,000	115,850,000
Purchase of marketable securities and investments	(158,378,000)	(579,654,000)	(61,438,000)
Acquisitions of businesses, net of cash acquired	(2,051,000)	(5,476,000)	(36,343,000)
Other	(15,609,000)	28,000	(99,797,000)
Net cash used in investing activities	(53,762,000)	62,336,000	(96,307,000)
Cash flows from financing activities:
Proceeds from issuance of debt	(638,000)	0	0
Repayment of debt	(196,000)	0	0
Proceeds from exercise of stock-based compensation awards	0	0
Dividends paid	(21,000)	(20,000)	(11,000)
Repurchase of common stock	0	0	0
Other	653,000	(867,000)	55,000
Net cash used in financing activities	(202,000)	(887,000)	44,000
Effect of exchange rate changes on cash and cash equivalents	(61,000)	(5,158,000)	4,153,000
Net increase (decrease) in cash and cash equivalents	(1,109,000)	(18,065,000)	33,192,000
Cash and cash equivalents at beginning of year	51,801,000	69,866,000	36,674,000
Cash and cash equivalents at end of year	50,692,000	51,801,000	69,866,000
Eliminations [Member]
Cash flows from operating activities:
Net income	(348,268,000)	(833,815,000)	(344,302,000)
Adjustments to reconcile net income to net cash provided by (used in) operating activities:
Depreciation	0	0	0
Amortization of intangible assets	0	0	0
Stock-based compensation	0	0	0
Deferred income taxes	0	0	0
Change in current assets and liabilities, net of acquisitions of businesses:
Accounts receivable, net	0	0	0
Inventories, net	6,629,000	(2,970,000)	(8,532,000)
Uniforms and other rental items in service	(2,148,000)	(5,115,000)	5,819,000
Prepaid expenses	0	0	0
Accounts payable	(3,000)	0	(4,000)
Accrued compensation and related liabilities	0	0	0
Accrued liabilities	19,000	18,000	16,000
Income taxes, current	0	0	0
Net cash provided by operating activities	(343,771,000)	(841,882,000)	(347,003,000)
Cash flows from investing activities:
Capital expenditures	0	0	0
Proceeds from redemption of marketable securities	0	0	0
Purchase of marketable securities and investments	11,672,000	412,839,000	55,466,000
Acquisitions of businesses, net of cash acquired	0	0	0
Other	332,118,000	429,061,000	291,553,000
Net cash used in investing activities	343,790,000	841,900,000	347,019,000
Cash flows from financing activities:
Proceeds from issuance of debt	0	786,000	0
Repayment of debt	(19,000)	(804,000)	(16,000)
Proceeds from exercise of stock-based compensation awards	0	0
Dividends paid	0	0	0
Repurchase of common stock	0	0	0
Other	0	0	0
Net cash used in financing activities	(19,000)	(18,000)	(16,000)
Effect of exchange rate changes on cash and cash equivalents	0	0	0
Net increase (decrease) in cash and cash equivalents	0	0	0
Cash and cash equivalents at beginning of year	0	0	0
Cash and cash equivalents at end of year	$ 0	$ 0	$ 0