Equity (Tables)

6 Months Ended

Jun. 30, 2012

Equity

Schedule of equity-based compensation expense

	Three months ended				Six months ended
	June 30,				June 30,
	2012		2011		2012		2011
Equity-based compensation expense	$	4,014	$	3,717	$	7,144	$	6,517

Summary of restricted stock awards and restricted stock unit activity

	Shares  (000’s)		Weighted- Average  Grant-Date  Fair Value
Nonvested as of December 31, 2011	618		$	33.61
Granted	307		32.64
Vested	(133	)	19.42
Forfeited (including cancelled awards)	(31	)	32.79
Nonvested as of June 30, 2012	761		$	35.73

Summary of stock option awards activity

	Shares  (000s)		Weighted- Average  Exercise  Price		Aggregate  Intrinsic  Value  (000s)		Weighted-  Average  Remaining  Contractual  Life  (in years)
Outstanding as of December 31, 2011	2,106		$	25.58
Granted	687		32.56
Exercised	(143	)	15.05
Forfeited (including cancelled options)	(52	)	31.06
Outstanding as of June 30, 2012	2,598		$	27.90	$	22,593	6.7
Options exercisable as of June 30, 2012	1,414		$	20.89	$	20,823	4.8