Stock-Based Compensation (Tables)

3 Months Ended

Mar. 31, 2013

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 January 1, 2013	13,446,719		$	43.39	7.08	$	268,596
Options exercised	(1,043,444	)	31.30
Options forfeited	(58,500	)	50.58
Options outstanding at March 31, 2013	12,344,775		44.37		7.06	373,596
Vested and non-vested options expected to vest atMarch 31, 2013	11,297,092		$	44.09	6.98	$	345,248
Exercisable options at March 31, 2013	4,460,718		$	38.38	5.59	$	161,774

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

	Options		Weighted Average Fair Value at Grant Date
Non-vested options at January 1, 2013	7,951,177		$	13.36
Options vested	(8,620	)	15.62
Options forfeited	(58,500	)	13.50
Non-vested options at March 31, 2013	7,884,057		13.35

Summary of activity in the option plans

	Three months ended March 31,
	2013		2012
Total intrinsic value of stock options exercised	$	40,542	$	24,819
Total fair value of stock options vested	135		119