Stock-Based Compensation (Tables)

3 Months Ended

Mar. 31, 2014

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, 2014	13,422,226		$	51.80	7.08	$	501,706
Options granted	32,500		89.13
Options exercised	(314,966	)	40.41
Options forfeited	(51,460	)	59.80
Options outstanding at March 31, 2014	13,088,300		52.14		6.89	517,164
Vested and non-vested options expected to vest atMarch 31, 2014	11,928,448		$	51.50	6.80	$	478,893
Exercisable options at March 31, 2014	5,097,339		$	41.15	5.36	$	257,418

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, 2014	8,016,921		$	14.77
Options granted	32,500		21.23
Options vested	(7,000	)	16.98
Options forfeited	(51,460	)	14.82
Non-vested options at March 31, 2014	7,990,961		14.79

Summary of activity in the option plans

	Three months ended March 31,
	2014		2013
Total intrinsic value of stock options exercised	$	15,560	$	40,542
Total fair value of stock options vested	119		135