Goodwill, Service Contracts and Other Assets (Details 3) (USD $) In Thousands, unless otherwise specified	Feb. 28, 2013		May 31, 2012
Information regarding service contracts and other assets
Service contracts, Net	$ 93,573		$ 76,822
Other Assets, Carrying Amount	198,270		186,062
Other Assets, Accumulated Amortization	76,827		73,226
Other Assets, Net	121,443		112,836
Noncompete agreements [Member]
Information regarding service contracts and other assets
Other Assets, Carrying Amount	77,661		76,036
Other Assets, Accumulated Amortization	72,468		69,954
Other Assets, Net	5,193		6,082
Investments [Member]
Information regarding service contracts and other assets
Other Assets, Carrying Amount	99,107	[1]	90,198	[1]
Other Assets, Accumulated Amortization	0	[1]	0	[1]
Other Assets, Net	99,107	[1]	90,198	[1]
Other [Member]
Information regarding service contracts and other assets
Other Assets, Carrying Amount	21,502		19,828
Other Assets, Accumulated Amortization	4,359		3,272
Other Assets, Net	17,143		16,556
Service Contracts [Member]
Information regarding service contracts and other assets
Service contracts, Carrying Amount	416,866		384,622
Service contracts, Accumulated Amortization	323,293		307,800
Service contracts, Net	$ 93,573		$ 76,822

[1] Investments at February 28, 2013, include the cash surrender value of insurance policies of $70.5 million, equity method investments of $27.7 million and cost method investments of $0.9 million. In the second quarter of fiscal 2013, Cintas sold stock of an equity method investment for a gain of $8.5 million. No further sales occurred in the third quarter of fiscal 2013. 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.