Supplemental Guarantor Information (Condensed Consolidating Statement of Cash Flows) (Details) (USD $)	12 Months Ended
	May 31, 2014	May 31, 2013	May 31, 2012
Cash flows from operating activities:
Net income	$ 374,442,000	$ 315,442,000	$ 297,637,000
Adjustments to reconcile net income to net cash provided by (used in) operating activities:
Depreciation	168,220,000	165,664,000	155,831,000
Amortization of intangible assets	22,642,000	23,713,000	38,334,000
Stock-based compensation	29,875,000	23,310,000	20,312,000
Gain on deconsolidation of Shredding	(106,441,000)	0	0
Shredding transaction asset impairment charge	16,143,000	0	0
Shredding transaction costs	26,057,000	0	0
Deferred income taxes	47,109,000	48,023,000	56,727,000
Change in current assets and liabilities, net of acquisitions of businesses:
Accounts receivable, net	(56,231,000)	(42,704,000)	(24,261,000)
Inventories, net	(11,062,000)	10,997,000	(2,330,000)
Uniforms and other rental items in service	(11,435,000)	(44,179,000)	(60,279,000)
Prepaid expenses	(2,177,000)	(3,281,000)	(1,496,000)
Accounts payable	30,446,000	25,023,000	(12,557,000)
Accrued compensation and related liabilities	10,931,000	(13,161,000)	11,625,000
Accrued liabilities	54,237,000	31,873,000	(20,371,000)
Income taxes, current	15,213,000	12,028,000	10,690,000
Net cash provided by operating activities	607,969,000	552,748,000	469,862,000
Cash flows from investing activities:
Capital expenditures	(145,580,000)	(196,486,000)	(160,802,000)
Proceeds from redemption of marketable securities	54,196,000	161,478,000	665,016,000
Purchase of marketable securities and investments	(65,858,000)	(178,464,000)	(585,655,000)
Proceeds from Shredding transaction, net of cash contributed	179,359,000	0	0
Acquisitions of businesses, net of cash acquired	(33,441,000)	(69,370,000)	(24,864,000)
Other	(5,219,000)	(1,339,000)	2,011,000
Net cash provided by (used in) investing activities	(16,543,000)	(284,181,000)	(104,294,000)
Cash flows from financing activities:
Proceeds from issuance of debt	0	250,000,000	0
Repayment of debt	(8,187,000)	(225,636,000)	(1,323,000)
Proceeds from exercise of stock-based compensation awards	41,902,000	14,807,000	3,341,000
Dividends paid	(93,320,000)	(79,744,000)	(70,820,000)
Repurchase of common stock	(370,599,000)	(215,681,000)	(392,328,000)
Other	469,000	196,000	555,000
Net cash used in financing activities	(429,735,000)	(256,058,000)	(460,575,000)
Effect of exchange rate changes on cash and cash equivalents	(676,000)	(61,000)	(3,274,000)
Net increase (decrease) in cash and cash equivalents	161,015,000	12,448,000	(98,281,000)
Cash and cash equivalents at beginning of year	352,273,000	339,825,000	438,106,000
Cash and cash equivalents at end of year	513,288,000	352,273,000	339,825,000
Cintas Corporation [Member]
Cash flows from operating activities:
Net income	374,442,000	315,442,000	297,637,000
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	29,875,000	23,310,000	20,312,000
Gain on deconsolidation of Shredding	0
Shredding transaction asset impairment charge	0
Shredding transaction costs	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	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	404,317,000	338,752,000	317,949,000
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
Proceeds from Shredding transaction, net of cash contributed	0
Acquisitions of businesses, net of cash acquired	0	0	0
Other	13,783,000	(60,918,000)	141,350,000
Net cash provided by (used in) investing activities	13,783,000	(60,918,000)	141,350,000
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	41,902,000	14,807,000	3,341,000
Dividends paid	(93,293,000)	(79,723,000)	(70,800,000)
Repurchase of common stock	(370,599,000)	(215,681,000)	(392,328,000)
Other	3,890,000	2,763,000	488,000
Net cash used in financing activities	(418,100,000)	(277,834,000)	(459,299,000)
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	162,263,000	98,748,000	165,559,000
Adjustments to reconcile net income to net cash provided by (used in) operating activities:
Depreciation	110,100,000	16,647,000	102,613,000
Amortization of intangible assets	20,547,000	21,077,000	33,114,000
Stock-based compensation	0	0	0
Gain on deconsolidation of Shredding	(111,661,000)
Shredding transaction asset impairment charge	0
Shredding transaction costs	0
Deferred income taxes	(2,000)	0	0
Change in current assets and liabilities, net of acquisitions of businesses:
Accounts receivable, net	(53,053,000)	(25,206,000)	(15,280,000)
Inventories, net	(14,735,000)	9,034,000	(5,635,000)
Uniforms and other rental items in service	(11,004,000)	(26,364,000)	(34,401,000)
Prepaid expenses	(386,000)	507,000	(2,154,000)
Accounts payable	25,573,000	(55,802,000)	(143,189,000)
Accrued compensation and related liabilities	5,778,000	(9,206,000)	8,659,000
Accrued liabilities	50,008,000	(5,416,000)	16,929,000
Income taxes, current	2,621,000	1,110,000	(4,357,000)
Net cash provided by operating activities	186,049,000	25,129,000	121,858,000
Cash flows from investing activities:
Capital expenditures	(123,978,000)	(39,975,000)	(116,954,000)
Proceeds from redemption of marketable securities	0	0	0
Purchase of marketable securities and investments	(152,913,000)	(683,000)	(2,740,000)
Proceeds from Shredding transaction, net of cash contributed	180,000,000
Acquisitions of businesses, net of cash acquired	(13,199,000)	(67,431,000)	(19,323,000)
Other	(50,446,000)	58,589,000	20,090,000
Net cash provided by (used in) investing activities	(160,536,000)	(49,500,000)	(118,927,000)
Cash flows from financing activities:
Proceeds from issuance of debt	0	250,000,000	0
Repayment of debt	(8,436,000)	(225,866,000)	(843,000)
Proceeds from exercise of stock-based compensation awards	0	0	0
Dividends paid	0	0	0
Repurchase of common stock	0	0	0
Other	1,952,000	(3,989,000)	1,508,000
Net cash used in financing activities	(6,484,000)	20,145,000	665,000
Effect of exchange rate changes on cash and cash equivalents	0	0	184,000
Net increase (decrease) in cash and cash equivalents	19,029,000	(4,226,000)	3,780,000
Cash and cash equivalents at beginning of year	54,511,000	58,737,000	54,957,000
Cash and cash equivalents at end of year	73,540,000	54,511,000	58,737,000
Subsidiary Guarantors [Member]
Cash flows from operating activities:
Net income	205,009,000	216,727,000	230,677,000
Adjustments to reconcile net income to net cash provided by (used in) operating activities:
Depreciation	44,856,000	135,345,000	40,613,000
Amortization of intangible assets	153,000	200,000	393,000
Stock-based compensation	0	0	0
Gain on deconsolidation of Shredding	0
Shredding transaction asset impairment charge	16,143,000
Shredding transaction costs	26,057,000
Deferred income taxes	47,373,000	53,916,000	56,411,000
Change in current assets and liabilities, net of acquisitions of businesses:
Accounts receivable, net	(1,300,000)	(15,326,000)	(4,985,000)
Inventories, net	4,839,000	(5,292,000)	4,685,000
Uniforms and other rental items in service	557,000	(11,590,000)	(19,286,000)
Prepaid expenses	(1,844,000)	(3,620,000)	950,000
Accounts payable	23,246,000	75,034,000	661,243,000
Accrued compensation and related liabilities	4,947,000	(3,977,000)	1,466,000
Accrued liabilities	4,897,000	38,099,000	(30,586,000)
Income taxes, current	9,902,000	206,000	4,712,000
Net cash provided by operating activities	384,835,000	479,722,000	946,293,000
Cash flows from investing activities:
Capital expenditures	(9,591,000)	(131,208,000)	(26,270,000)
Proceeds from redemption of marketable securities	5,659,000	13,899,000	0
Purchase of marketable securities and investments	(242,956,000)	(31,075,000)	(416,100,000)
Proceeds from Shredding transaction, net of cash contributed	0
Acquisitions of businesses, net of cash acquired	0	112,000	(65,000)
Other	8,108,000	(315,519,000)	(588,518,000)
Net cash provided by (used in) investing activities	(238,780,000)	(463,791,000)	(1,030,953,000)
Cash flows from financing activities:
Proceeds from issuance of debt	(2,445,000)	638,000	(786,000)
Repayment of debt	(106,000)	445,000	324,000
Proceeds from exercise of stock-based compensation awards	0	0	0
Dividends paid	0	0	0
Repurchase of common stock	0	0	0
Other	8,951,000	769,000	(574,000)
Net cash used in financing activities	6,400,000	1,852,000	(1,036,000)
Effect of exchange rate changes on cash and cash equivalents	0	0	1,700,000
Net increase (decrease) in cash and cash equivalents	152,455,000	17,783,000	(83,996,000)
Cash and cash equivalents at beginning of year	247,070,000	229,287,000	313,283,000
Cash and cash equivalents at end of year	399,525,000	247,070,000	229,287,000
Non-Guarantors [Member]
Cash flows from operating activities:
Net income	20,809,000	32,793,000	437,579,000
Adjustments to reconcile net income to net cash provided by (used in) operating activities:
Depreciation	13,264,000	13,672,000	12,605,000
Amortization of intangible assets	1,942,000	2,436,000	4,827,000
Stock-based compensation	0	0	0
Gain on deconsolidation of Shredding	5,220,000
Shredding transaction asset impairment charge	0
Shredding transaction costs	0
Deferred income taxes	(262,000)	(5,893,000)	316,000
Change in current assets and liabilities, net of acquisitions of businesses:
Accounts receivable, net	(1,878,000)	(2,172,000)	(3,996,000)
Inventories, net	450,000	626,000	1,590,000
Uniforms and other rental items in service	(973,000)	(4,077,000)	(1,477,000)
Prepaid expenses	53,000	(168,000)	(292,000)
Accounts payable	(18,374,000)	5,794,000	(530,611,000)
Accrued compensation and related liabilities	206,000	22,000	1,500,000
Accrued liabilities	(689,000)	(829,000)	(6,732,000)
Income taxes, current	2,690,000	10,712,000	10,335,000
Net cash provided by operating activities	22,458,000	52,916,000	(74,356,000)
Cash flows from investing activities:
Capital expenditures	(12,011,000)	(25,303,000)	(17,578,000)
Proceeds from redemption of marketable securities	48,537,000	147,579,000	665,016,000
Purchase of marketable securities and investments	(48,537,000)	(158,378,000)	(579,654,000)
Proceeds from Shredding transaction, net of cash contributed	(641,000)
Acquisitions of businesses, net of cash acquired	(20,242,000)	(2,051,000)	(5,476,000)
Other	12,173,000	(15,609,000)	28,000
Net cash provided by (used in) investing activities	(20,721,000)	(53,762,000)	62,336,000
Cash flows from financing activities:
Proceeds from issuance of debt	2,445,000	(638,000)	0
Repayment of debt	376,000	(196,000)	0
Proceeds from exercise of stock-based compensation awards	0	0	0
Dividends paid	(27,000)	(21,000)	(20,000)
Repurchase of common stock	0	0	0
Other	(14,324,000)	653,000	(867,000)
Net cash used in financing activities	(11,530,000)	(202,000)	(887,000)
Effect of exchange rate changes on cash and cash equivalents	(676,000)	(61,000)	(5,158,000)
Net increase (decrease) in cash and cash equivalents	(10,469,000)	(1,109,000)	(18,065,000)
Cash and cash equivalents at beginning of year	50,692,000	51,801,000	69,866,000
Cash and cash equivalents at end of year	40,223,000	50,692,000	51,801,000
Eliminations [Member]
Cash flows from operating activities:
Net income	(388,081,000)	(348,268,000)	(833,815,000)
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
Gain on deconsolidation of Shredding	0
Shredding transaction asset impairment charge	0
Shredding transaction costs	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	(1,616,000)	6,629,000	(2,970,000)
Uniforms and other rental items in service	(15,000)	(2,148,000)	(5,115,000)
Prepaid expenses	0	0	0
Accounts payable	1,000	(3,000)	0
Accrued compensation and related liabilities	0	0	0
Accrued liabilities	21,000	19,000	18,000
Income taxes, current	0	0	0
Net cash provided by operating activities	(389,690,000)	(343,771,000)	(841,882,000)
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	378,548,000	11,672,000	412,839,000
Proceeds from Shredding transaction, net of cash contributed	0
Acquisitions of businesses, net of cash acquired	0	0	0
Other	11,163,000	332,118,000	429,061,000
Net cash provided by (used in) investing activities	389,711,000	343,790,000	841,900,000
Cash flows from financing activities:
Proceeds from issuance of debt	0	0	786,000
Repayment of debt	(21,000)	(19,000)	(804,000)
Proceeds from exercise of stock-based compensation awards	0	0	0
Dividends paid	0	0	0
Repurchase of common stock	0	0	0
Other	0	0	0
Net cash used in financing activities	(21,000)	(19,000)	(18,000)
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