DaVita Inc. stock-based compensation and shareholders' equity (Tables)

12 Months Ended

Dec. 31, 2011

Summary of Status of Awards Under Stock-Based Compensation Plans and Agreements

A combined summary of the status of awards under the Company’s stock-based compensation plans, including base shares for stock-settled stock appreciation rights and shares subject to stock option and stock unit awards, is as follows:

	Year ended December 31, 2011
	Stock appreciation rights and stock options							Stock units
	Awards			Weighted average exercise price		Weighted average remaining contractual life		Awards			Weighted average remaining contractual life
Outstanding at beginning of year		11,013,487		$	51.94				501,564
Granted		2,707,500			82.17				150,246
Exercised		(3,032,329	)		51.46				(78,106	)
Cancelled		(483,094	)		59.59				(60,596	)
Outstanding at end of period		10,205,564		$	59.74		2.6		513,108			1.5
Awards exercisable at end of period		4,348,803		$	50.62		1.7		3,446			0.6
Weighted-average fair value of awards granted during 2011	$	21.93						$	85.28
Weighted-average fair value of awards granted during 2010	$	15.87						$	62.85
Weighted-average fair value of awards granted during 2009	$	12.08						$	54.31

Summary of Range of Exercise Prices

Range of exercise prices	Awards outstanding		Weighted average exercise price		Awards exercisable		Weighted average exercise price
$ 0.00–$ 0.01		513,108	$	—		3,446	$	—
$40.01–$50.00		3,856,250		45.69		2,254,496		45.54
$50.01–$60.00		1,868,878		52.43		1,453,292		52.47
$60.01–$70.00		1,993,936		64.40		621,015		64.04
$70.01–$80.00		397,500		74.20		20,000		72.52
$80.01–$90.00		2,089,000		85.01		—		—
Total		10,718,672	$	56.88		4,352,249	$	50.58

Summary of Weighted Average Valuation Inputs

A summary of the weighted average valuation inputs described above used for estimating the grant-date fair value of stock options and stock-settled stock appreciation rights granted in the periods indicated is as follows:

	Year ended December 31,
	2011			2010			2009
Expected term		4.2 years			3.5 years			3.5 years
Expected volatility		30	%		30	%		32	%
Expected dividend yield		0.0	%		0.0	%		0.0	%
Risk-free interest rate		1.6	%		1.7	%		1.8	%

Effects of Changes in DaVita Inc's Ownership Interest on Company's Equity

The effects of changes in DaVita Inc.’s ownership interest on the Company’s equity are as follows:

	Year ended December 31, 2011			Year ended December 31, 2010			Year ended December 31, 2009
Net income attributable to DaVita Inc.	$	478,001		$	405,683		$	422,684
Decrease in paid-in capital for sales of noncontrolling interest in several joint ventures		(1,299	)		(298	)		(529	)
Decrease in paid-in capital for the purchase of a noncontrolling interest in several joint ventures		(9,486	)		(5,537	)		(3,721	)
Net transfer to noncontrolling interests		(10,785	)		(5,835	)		(4,250	)
Change from net income attributable to DaVita Inc. and transfers to noncontrolling interests	$	467,216		$	399,848		$	418,434