Stock-Based Compensation (Tables)

3 Months Ended

Mar. 31, 2012

Stock-Based Compensation

Schedule of stock option activity

	Options		Weighted Average Exercise Price		Weighted Average Remaining Contractual Term (in years)	Aggregate Intrinsic Value
Options outstanding at December 31, 2011	14,016,900		$	38.00	6.89	$	125,067
Options exercised	(853,460	)	26.23
Options forfeited	(123,000	)	38.53
Options outstanding at March 31, 2012	13,040,440		$	38.77	6.79	$	273,830
Vested and non-vested options expected to vest at March 31, 2012	12,218,010		$	38.37	6.69	$	261,463
Exercisable options at March 31, 2012	5,533,864		$	32.32	5.29	$	151,911

Summary of status of non-vested options and changes during the year

	Options		Weighted Average Fair Value at Grant Date
Non-vested options at December 31, 2011	7,636,576		$	13.41
Options vested	(7,000	)	16.98
Options forfeited	(123,000	)	12.52
Non-vested options at March 31, 2012	7,506,576		$	13.43

Summary of activity in the option plans

	Three months ended March 31,
	2012		2011
Total intrinsic value of stock options exercised	$	24,819	$	19,663
Total fair value of stock options vested	119		—