Supplemental Guarantor Information - Condensed Consolidating Balance Sheet (Details) - USD ($) $ in Thousands	May 31, 2018		May 31, 2017		May 31, 2016	May 31, 2015
Current assets:
Cash and cash equivalents	$ 138,724		$ 169,266		$ 139,357	$ 417,073
Marketable securities	0		22,219
Accounts receivable, net	804,583		736,008
Inventories, net	280,347		278,218
Uniforms and other rental items in service	702,261		635,702
Income taxes, current	19,634		44,320
Prepaid expenses and other current assets	32,383		30,132
Assets held for sale	0		38,613
Total current assets	1,977,932		1,954,478
Property and equipment, net	1,382,730		1,323,501
Investments	175,581	[1]	164,788	[2]
Goodwill	2,846,888		2,782,335		1,276,076
Service contracts, net	545,768		586,988
Other assets, net	29,315		31,967
Total assets	6,958,214		6,844,057		4,098,815
Current liabilities:
Accounts payable	215,074		177,051
Accrued compensation and related liabilities	140,654		149,635
Accrued liabilities	420,129		429,809
Liabilities held for sale	0		11,457
Debt due within one year	0		362,900
Total current liabilities	775,857		1,130,852
Long-term liabilities:
Debt due after one year	2,535,309		2,770,624
Deferred income taxes	352,581		469,328
Accrued liabilities	277,941		170,460
Total long-term liabilities	3,165,831		3,410,412
Total shareholders' equity	3,016,526		2,302,793		1,842,659	1,932,455
Total liabilities and shareholders' equity	6,958,214		6,844,057
Corporate
Current assets:
Total assets	138,724		230,098		249,822
Eliminations
Current assets:
Cash and cash equivalents	0		0		0	0
Marketable securities			0
Accounts receivable, net	0		0
Inventories, net	0		(1,386)
Uniforms and other rental items in service	(18,589)		(18,993)
Income taxes, current	0		0
Prepaid expenses and other current assets	0		0
Assets held for sale			0
Total current assets	(18,589)		(20,379)
Property and equipment, net	0		0
Investments	(6,407,479)	[1]	(6,402,479)	[2]
Goodwill	(112)		(112)
Service contracts, net	0		0
Other assets, net	(6,591,606)		(5,000,837)
Total assets	(13,017,786)		(11,423,807)
Current liabilities:
Accounts payable	37,947		38,108
Accrued compensation and related liabilities	0		0
Accrued liabilities	0		0
Liabilities held for sale			0
Debt due within one year			0
Total current liabilities	37,947		38,108
Long-term liabilities:
Debt due after one year	0		0
Deferred income taxes	0		0
Accrued liabilities	0		0
Total long-term liabilities	0		0
Total shareholders' equity	(13,055,733)		(11,461,915)
Total liabilities and shareholders' equity	(13,017,786)		(11,423,807)
Cintas Corporation | Corporate
Current assets:
Cash and cash equivalents	0		0		0	0
Marketable securities			0
Accounts receivable, net	0		0
Inventories, net	0		0
Uniforms and other rental items in service	0		0
Income taxes, current	0		0
Prepaid expenses and other current assets	0		0
Assets held for sale			0
Total current assets	0		0
Property and equipment, net	0		0
Investments	321,083	[1]	321,083	[2]
Goodwill	0		0
Service contracts, net	0		0
Other assets, net	2,230,196		1,516,463
Total assets	2,551,279		1,837,546
Current liabilities:
Accounts payable	(465,247)		(465,247)
Accrued compensation and related liabilities	0		0
Accrued liabilities	0		0
Liabilities held for sale			0
Debt due within one year			0
Total current liabilities	(465,247)		(465,247)
Long-term liabilities:
Debt due after one year	0		0
Deferred income taxes	0		0
Accrued liabilities	0		0
Total long-term liabilities	0		0
Total shareholders' equity	3,016,526		2,302,793
Total liabilities and shareholders' equity	2,551,279		1,837,546
Corp. 2
Current assets:
Investments	17,600		29,000
Corp. 2 | Corporate
Current assets:
Cash and cash equivalents	44,499		48,658		57,894	74,632
Marketable securities			0
Accounts receivable, net	620,920		543,769
Inventories, net	225,581		243,677
Uniforms and other rental items in service	585,108		531,295
Income taxes, current	5,546		16,173
Prepaid expenses and other current assets	9,453		13,234
Assets held for sale			23,095
Total current assets	1,491,107		1,419,901
Property and equipment, net	900,014		851,018
Investments	3,595,668	[1]	3,605,457	[2]
Goodwill	0		0
Service contracts, net	468,283		505,698
Other assets, net	593		14,705
Total assets	6,455,665		6,396,779
Current liabilities:
Accounts payable	(1,724,844)		(1,596,731)
Accrued compensation and related liabilities	104,560		94,505
Accrued liabilities	88,949		191,819
Liabilities held for sale			11,457
Debt due within one year			362,900
Total current liabilities	(1,531,335)		(936,050)
Long-term liabilities:
Debt due after one year	2,534,919		2,770,234
Deferred income taxes	215,881		0
Accrued liabilities	63,073		28,384
Total long-term liabilities	2,813,873		2,798,618
Total shareholders' equity	5,173,127		4,534,211
Total liabilities and shareholders' equity	6,455,665		6,396,779
Subsidiary Guarantors
Current assets:
Investments	158,000		135,800
Subsidiary Guarantors | Corporate
Current assets:
Cash and cash equivalents	60,310		17,302		55,391	248,716
Marketable securities			0
Accounts receivable, net	120,767		137,881
Inventories, net	38,844		21,466
Uniforms and other rental items in service	81,494		78,012
Income taxes, current	9,258		25,138
Prepaid expenses and other current assets	21,688		16,188
Assets held for sale			15,518
Total current assets	332,361		311,505
Property and equipment, net	370,186		364,724
Investments	950,239	[1]	929,657	[2]
Goodwill	2,579,769		2,742,898
Service contracts, net	0		0
Other assets, net	4,381,476		3,489,653
Total assets	8,614,031		7,838,437
Current liabilities:
Accounts payable	2,395,434		2,292,388
Accrued compensation and related liabilities	24,878		42,866
Accrued liabilities	308,485		219,303
Liabilities held for sale			0
Debt due within one year			0
Total current liabilities	2,728,797		2,554,557
Long-term liabilities:
Debt due after one year	0		0
Deferred income taxes	104,559		436,613
Accrued liabilities	198,181		140,923
Total long-term liabilities	302,740		577,536
Total shareholders' equity	5,582,494		4,706,344
Total liabilities and shareholders' equity	8,614,031		7,838,437
Non- Guarantors | Corporate
Current assets:
Cash and cash equivalents	33,915		103,306		$ 26,072	$ 93,725
Marketable securities			22,219
Accounts receivable, net	62,896		54,358
Inventories, net	15,922		14,461
Uniforms and other rental items in service	54,248		45,388
Income taxes, current	4,830		3,009
Prepaid expenses and other current assets	1,242		710
Assets held for sale			0
Total current assets	173,053		243,451
Property and equipment, net	112,530		107,759
Investments	1,716,070	[1]	1,711,070	[2]
Goodwill	267,231		39,549
Service contracts, net	77,485		81,290
Other assets, net	8,656		11,983
Total assets	2,355,025		2,195,102
Current liabilities:
Accounts payable	(28,216)		(91,467)
Accrued compensation and related liabilities	11,216		12,264
Accrued liabilities	22,695		18,687
Liabilities held for sale			0
Debt due within one year			0
Total current liabilities	5,695		(60,516)
Long-term liabilities:
Debt due after one year	390		390
Deferred income taxes	32,141		32,715
Accrued liabilities	16,687		1,153
Total long-term liabilities	49,218		34,258
Total shareholders' equity	2,300,112		2,221,360
Total liabilities and shareholders' equity	$ 2,355,025		$ 2,195,102

[1] Investments include inter company investment activity. Corp 2 and Subsidiary Guarantors hold $17.6 million and $158.0 million, respectively, of the $175.6 million consolidated net investments.

[2] Investments include inter company investment activity. Corp 2 and Subsidiary Guarantors hold $29.0 million and $135.8 million, respectively, of the $164.8 million consolidated net investments.