Stock Incentive Plans (Tables)

12 Months Ended

Dec. 31, 2012

Disclosure of Compensation Related Costs, Share-based Payments [Abstract]

Schedule of information relating to options

The following table sets forth information relating to such options during 2012, 2011, and 2010:

Stock Option Activity	Number Of Shares		Average Exercise Price		Weighted- Average Grant Date Fair Value
Balance at January 1, 2010	4,172,206		$	14.19
Options exercised	(837,039	)	12.42
Options forfeited	(170,212	)	18.60
Options terminated	(52,100	)	13.09
Options granted	1,355,486		27.75		10.13
Balance at December 31, 2010	4,468,341		18.48
Options exercised	(765,693	)	15.76
Options forfeited	(45,369	)	22.30
Options terminated	(7,011	)	8.03
Options granted	1,287,152		42.18		15.44
Balance at December 31, 2011	4,937,420		25.08
Options exercised	(1,679,359	)	19.14
Options forfeited	(51,573	)	37.67
Options terminated	(10,995	)	15.74
Options granted	828,991		49.01		16.67
Balance at December 31, 2012	4,024,484		32.33

Schedule of summary of non-vested option activity for the period

The following is a summary of non-vested option activity for the year ended December 31, 2012:

Stock Option Activity	Number Of Shares		Weighted- Average Grant Date Fair Value
Non-vested options outstanding at beginning of year	2,615,148		$	11.57
Granted	828,991		16.67
Vested / exercised	(1,313,898	)	9.67
Forfeited	(62,568	)	11.61
Non vested options outstanding at end of year	2,067,673		14.90

Schedule of stock options outstanding and exercisable by exercise price range

A summary of our stock options outstanding and exercisable at December 31, 2012, follows:

Exercise Price Range	Number Outstanding	Number Exercisable	Outstanding Weighted- Average Remaining Contractual Life (Years)	Exercisable Weighted- Average Exercise Price
$0 - $10	740,401	740,401	1.35	$	9.79
$10 - $20	286,915	286,915	0.71	19.63
$20 - $30	1,027,008	608,464	2.33	27.75
$30 - $40	16,192	5,397	3.60	37.06
$40 - $50	1,924,181	315,634	3.83	42.24
$50 - $60	5,000	—	4.54	—
$60 - $70	24,787	—	4.93	—
	4,024,484	1,956,811	2.78	22.12

Schedule of the assumptions used for estimating the fair value of stock options granted during the period

The following summarizes the assumptions used for estimating the fair value of stock options granted during 2012, 2011 and 2010, respectively.

	2012	2011	2010
Expected volatility	35.8% - 46.4%	46.5% - 50.7%	44.7% - 51.2%
Weighted average expected volatility	40.6%	48.7%	47.8%
Expected term	3.00 - 4.00 years	3.00 - 4.00 years	3.00 - 4.00 years
Risk-free rate	0.55%	1.43%	1.87%
Dividend yield	—%	—%	—%