Common Stock (Tables)

12 Months Ended

Dec. 31, 2011

Common Stock [Abstract]

Schedule Of Information Related To Stock Repurchase Programs

	Additional Shares Authorized For Repurchase		Total number of shares purchased(a)		Average price paid per share for forfeited restricted shares		Total number of shares purchased as part of publicly announced programs		Average price paid per share for shares purchased as part of publicly announced program		Aggregate purchase price paid (in thousands)		Maximum number of shares that may yet be purchased under the program
Balance as of January 1, 2009														4,713,548
2009		—		2,574,209	$	0.01		2,561,209	$	24.71	$	63,288		2,152,339
2010		—		301,933	$	0.01		293,933	$	39.22	$	11,528		1,858,406
2011		—		1,602,286	$	0.01		1,602,286	$	37.75	$	60,482		256,120
Total for three year period ended December 31, 2011		—		4,478,428	$	0.01		4,457,428	$	30.35	$	135,298

(a) During 2010 and 2009, there were 8,000 and 13,000, respectively, of restricted shares that were forfeited by former employees pursuant to the terms of our restricted stock purchase plan which are included in the total number of shares purchased. No such forfeitures occurred during 2011.

Schedule Of Weighted-Average Assumptions Fair Value Of Option Grants

Year Ended December 31,	2011			2010			2009
Volatility		29	%		27	%		28	%
Interest rate		2	%		3	%		3	%
Expected life (years)		3.5			3.6			3.6
Forfeiture rate		9	%		10	%		10	%
Dividend yield		0.7	%		0.7	%		0.7	%

Schedule Of Stock Option Activity

Outstanding Options	Number of Shares			Average Option Price		Range (High-Low)
Balance, January 1, 2009		8,116,326		$	22.68	$	31.70 -$16.22
Granted		2,635,000		$	31.18	$	31.18 -$31.18
Exercised		(1,582,376	)	$	23.71	$	29.89 -$16.22
Cancelled		(366,500	)	$	22.84	$	29.89 -$16.22
Balance, January 1, 2010		8,802,450		$	25.03	$	31.70 -$16.22
Granted		94,000		$	30.40	$	32.28 -$30.32
Exercised		(2,000,250	)	$	24.87	$	31.70 -$16.22
Cancelled		(301,250	)	$	24.91	$	31.18 -$16.22
Balance, January 1, 2011		6,594,950		$	25.16	$	32.28 -$16.22
Granted		2,894,500		$	43.66	$	54.79 -$38.12
Exercised		(1,563,255	)	$	26.38	$	32.28 -$16.22
Cancelled		(367,250	)	$	32.60	$	46.97 -$16.22
Balance, December 31, 2011		7,558,945		$	31.63	$	54.79 -$16.22
Outstanding options vested and exercisable as of December 31, 2011		2,979,945		$	23.82	$	31.18 -$16.22

Schedule Of Information About Unvested Options

	Shares			Weighted Average Grant Date Fair Value
Unvested options as of January 1, 2011		3,799,250		$	5.80
Granted		2,894,500		$	11.62
Vested		(1,757,500	)	$	5.26
Cancelled		(357,250	)	$	8.19
Unvested options as of December 31, 2011		4,579,000		$	9.50

Schedule Of Information About All Outstanding Options And Exercisable Options

	Options Outstanding		Options Exercisable
Number		7,558,945		2,979,945
Weighted average exercise price	$	31.63	$	23.82
Aggregate intrinsic value as of December 31, 2011	$	67,870,455	$	44,833,019
Weighted average remaining contractual life		2.8		1.8

Schedule Of Weighted Average Remaining Contractual Life For Options Outstanding And Weighted Average Exercise Price Per Share For Exercisable Options

	Options Outstanding						Exercisable Options				Expected to Vest Options(a)
Exercise Price	Shares		Weighted Average Exercise Price Per Share		Weighted Average Remaining Contractual Life (in Years)		Shares		Weighted Average Exercise Price Per Share		Shares		Weighted Average Exercise Price Per Share
$16.22 – $24.45		2,642,825	$	19.56		1.5		2,050,825	$	20.53		537,891	$	16.22
$25.32 – $29.26		29,500		26.80		1.1		17,750		26.59		10,676		27.12
$29.60 – $32.28		2,139,120		31.15		2.9		911,370		31.16		1,115,534		31.14
$38.12 – $43.67		2,728,000		43.59		4.1		—		N/A		2,478,661		43.59
$46.79 – $54.79		19,500		52.99		4.3		—		N/A		17,718		52.99
Total		7,558,945	$	31.63		2.8		2,979,945	$	23.82		4,160,480	$	36.71

(a) Assumes a weighted average forfeiture rate of 9.14%.