Share-Based Compensation (Tables)

12 Months Ended

Dec. 31, 2011

Share-Based Compensation [Abstract]

Summary of stock option activity

	Stock Options			Weighted- Average Exercise Price		Weighted- Average Remaining Contractual Term (Years)		Aggregate Intrinsic Value
Outstanding at December 31, 2010		3,323		$	16.45
Granted		894			15.98
Exercised		(395	)		10.12
Forfeited/Canceled		(46	)		23.25
Outstanding at December 31, 2011		3,776		$	16.92		2.3	$	10,699
Exercisable at December 31, 2011		2,543		$	17.23		1.1	$	6,409
Vested and expected to vest at December 31, 2011.		3,720		$	16.93		2.2	$	4,097

Summary of options outstanding

Options Outstanding				Options Exercisable
Exercise Price	Number  Outstanding	Weighted-Avg. Remaining Contractual         Life	Weighted-Avg. Exercise Price	Number Exercisable	Weighted-Avg. Exercise Price
$6.26 - $7.97	706,928	1.0	$  7.01	706,928	$  7.01
$15.33 - $30.70	3,069,002	2.3	$19.20	1,835,694	$21.16
	3,775,930			2,542,622

Assumptions used to determine fair value of options granted

Expected volatility(1)	39.0	%
Weighted-average volatility(1)	39.0	%
Expected dividends	0.0	%
Expected term(2)	4.3 years
Risk-free rate(3)	0.79	%

(1) We estimated the volatility of our common stock on the date of grant based on both historical and implied volatility.

(2) The expected term represents the period of time that we expect options to be outstanding. In 2011, we estimated the expected term based upon the weighted-average of our historical experience.

(3) The risk-free interest rate is based on the implied yield in effect at the time of option grant on U.S. Treasury zero-coupon issues with equivalent remaining terms.

Summary of nonvested stock activity

	Shares			Grant Date Weighted- Average Fair Value Per Share
Outstanding at December 31, 2010		687		$	26.16
Granted		1,248		$	19.99
Vested		(336	)	$	28.81
Forfeited/Canceled		(83	)	$	21.33
Outstanding at December 31, 2011		1,516		$	20.76