Goodwill, Service Contracts and Other Assets (Details 3) (USD $) In Thousands, unless otherwise specified	Nov. 30, 2012		May 31, 2012
Information regarding service contracts and other assets
Service contracts, Net	$ 90,480		$ 76,822
Other Assets, Carrying Amount	194,116		186,062
Other Assets, Accumulated Amortization	76,047		73,226
Other Assets, Net	118,069		112,836
Noncompete agreements [Member]
Information regarding service contracts and other assets
Other Assets, Carrying Amount	77,469		76,036
Other Assets, Accumulated Amortization	72,068		69,954
Other Assets, Net	5,401		6,082
Investments [Member]
Information regarding service contracts and other assets
Other Assets, Carrying Amount	95,109	[1]	90,198	[1]
Other Assets, Accumulated Amortization	0	[1]	0	[1]
Other Assets, Net	95,109	[1]	90,198	[1]
Other [Member]
Information regarding service contracts and other assets
Other Assets, Carrying Amount	21,538		19,828
Other Assets, Accumulated Amortization	3,979		3,272
Other Assets, Net	17,559		16,556
Service Contracts [Member]
Information regarding service contracts and other assets
Service contracts, Carrying Amount	409,522		384,622
Service contracts, Accumulated Amortization	319,042		307,800
Service contracts, Net	$ 90,480		$ 76,822

[1] Investments at November 30, 2012, include the cash surrender value of insurance policies of $67.0 million, equity method investments of $27.2 million and cost method investments of $0.9 million. During the second quarter of fiscal 2013, Cintas sold stock of an equity method investment for a gain of $8.5 million. Investments at May 31, 2012, include the cash surrender value of insurance policies of $57.4 million, equity method investments of $31.9 million and cost method investments of $0.9 million.