Stock Incentive Plans and Stock Purchase Plan: (Tables)

12 Months Ended

Dec. 31, 2012

Schedule of Weighted Average Grant-Date Fair Values

The activity related to the Company’s restricted and deferred stock awards and the corresponding weighted average grant-date fair values for the year ended December 31, 2012 are as follows:


	Number of Shares			Weighted Average Fair Value
Non-vested shares at January 1, 2012		978,353		$	59.64
Awarded		465,317		$	60.11
Forfeited		(39,441	)	$	65.06
Vested		(423,331	)	$	54.30

Non-vested shares at December 31, 2012		980,898		$	61.94

Schedule of Weighted Average Assumptions for Expected Volatility, Expected Life, Risk-Free Interest Rate and Dividend Yield


	Years Ended December 31,
	2011	2010
Expected volatility	35%	35%
Expected life—officers (in years)	4.5	4.5
Expected life—other employees (in years)	3.5	3.5
Risk-free interest rate	1.9%	2.1% to 2.3%
Dividend yield	0%	0%

Schedule of Activity and Certain Other Information Related to Stock Option Awards

The activity and certain other information related to the Company’s stock option awards for the year ended December 31, 2012 are as follows:


	Number of Shares			Weighted Average Exercise Price		Weighted Average Remaining Contractual Term (in years)		Aggregate Intrinsic Value (in millions)
Outstanding at January 1, 2012		2,053,573		$	45.10
Granted		—			—
Canceled		(5,794	)	$	68.56
Exercised		(528,135	)	$	39.33			$	18.1

Outstanding at December 31, 2012		1,519,644		$	47.02		4.1	$	49.4

Exercisable at December 31, 2012		1,474,539		$	46.46		3.9	$	48.8