Stock-Based Compensation (Tables)

12 Months Ended

May 31, 2012

Share-based Compensation [Abstract]

Assumptions used to determine fair value of options

The fair value of these options was estimated at the date of grant using a Black-Scholes option-pricing model with the following assumptions:

	2012		2011		2010
Risk-free interest rate	2.4	%	2.5	%	3.9	%
Dividend yield	1.7	%	1.5	%	1.3	%
Expected volatility of Cintas' common stock	37.0	%	30.0	%	30.0	%
Expected life of the option in years	7.5		7.5		7.5

Stock options granted and outstanding under either the 2005 Equity Compensation Plan or under previously adopted plans

The information presented in the following table relates primarily to stock options granted and outstanding under either the 2005 Equity Compensation Plan or under previously adopted plans:

	Shares		Weighted Average Exercise Price
Outstanding, May 31, 2009 (1,914,710 shares exercisable)	6,359,424		$	38.91
Granted	1,070,798		28.52
Canceled	(963,016	)	35.98
Exercised	—		—
Outstanding, May 31, 2010 (1,838,530 shares exercisable)	6,467,206		37.63
Granted	2,030,764		32.42
Canceled	(833,267	)	38.76
Exercised	—		—
Outstanding, May 31, 2011 (1,945,207 shares exercisable)	7,664,703		36.12
Granted	1,638,907		36.26
Canceled	(1,591,480	)	36.90
Exercised	(103,013	)	32.66
Outstanding, May 31, 2012 (2,105,702 shares exercisable)	7,609,117		$	36.04

Information related to stock options outstanding

The following table summarizes the information related to stock options outstanding at May 31, 2012:

		Outstanding Options			Exercisable Options
Range of Exercise Prices	Number Outstanding	Average Remaining Option Life	Weighted Average Exercise Price		Number Exercisable	Weighted Average Exercise Price
$ 20.29 – $ 31.00	1,725,722	7.50	$	26.22	176,768	$	26.97
31.01 –  34.27	1,279,826	8.61	33.99		60,390	33.50
34.28 –   39.36	2,410,094	6.77	37.49		622,774	38.69
39.37 –    50.47	2,193,475	2.48	42.51		1,245,770	42.65
$ 20.29 – $ 50.47	7,609,117	6.01	$	36.04	2,105,702	$	39.90

Restricted stock awards granted and outstanding under either the 2005 Equity Compensation Plan or under previously adopted plans

The information presented in the following table relates to restricted stock awards granted and outstanding under either the 2005 Equity Compensation Plan or under previously adopted plans:

	Shares		Weighted Average Grant Price
Outstanding, unvested grants at May 31, 2009	981,369		$	30.29
Granted	597,514		24.63
Canceled	(53,278	)	27.85
Vested	(118,254	)	36.57
Outstanding, unvested grants at May 31, 2010	1,407,351		27.45
Granted	712,721		31.59
Canceled	(66,754	)	25.54
Vested	(135,936	)	39.26
Outstanding, unvested grants at May 31, 2011	1,917,382		28.22
Granted	452,267		35.95
Canceled	(188,685	)	30.62
Vested	(291,968	)	27.60
Outstanding, unvested grants at May 31, 2012	1,888,996		$	29.93