Stock-Based Compensation Plans (Tables)

9 Months Ended

Sep. 30, 2011

Summary of Stock Options Issued Pursuant to Stock Incentive Plans

A summary of stock options issued pursuant to the Company’s stock incentive plans is as follows:

		September 30,			September 30,		September 30,		September 30,
	Number of Shares			Weighted- Average Exercise Price		Weighted- Average Remaining Contractual Term (Years)		Aggregate Intrinsic Value of In-the-Money Options
Outstanding as of December 31, 2010		3,510,538		$	21.55
Granted		70,000			29.00
Exercised		(232,499	)		11.95
Forfeited		(22,351	)		20.19
Outstanding as of September 30, 2011		3,325,688		$	22.38		5.14	$	21,022,107
Exercisable as of September 30, 2011		2,267,032		$	22.40		4.55	$	15,405,992

Fair Value of Options Granted Estimated using the Black-Scholes Option-Pricing Model with Weighted-Average Assumptions

The fair value of options granted during the nine months ended September 30, 2011 and 2010 was estimated on the date of grant using the Black-Scholes option-pricing model, a pricing model acceptable under U.S. GAAP, with the following weighted-average assumptions:

		September 30,			September 30,
	Nine Months Ended			Nine Months Ended
	September 30, 2011			September 30, 2010
Expected life (years)		5.50			5.63
Interest rate		1.6	%		2.3	%
Volatility		50.8	%		51.7	%
Dividend yield		—			—

Summary of Nonvested Long-Term Incentive Program Performance Share Awards ("LTIP performance shares") Outstanding

A summary of nonvested long-term incentive program performance share awards (“LTIP performance shares”) outstanding as of September 30, 2011 and changes during the period are as follows:

		September 30,			September 30,
Nonvested LTIP Performance Shares	Number of Shares at Expected Attainment			Weighted- Average Grant Date Fair Value
Nonvested as of December 31, 2010		499,035		$	20.57
Forfeited		(27,274	)		18.69
Nonvested as of September 30, 2011		471,761		$	20.72

Summary of Nonvested Restricted Share Awards ("RSAs") and Changes During the Period

A summary of nonvested restricted share awards (“RSAs”) as of September 30, 2011 and changes during the period are as follows:

		September 30,			September 30,
Nonvested Restricted Share Awards	Number of Restricted Share Awards			Weighted-Average Grant Date Fair Value
Nonvested as of December 31, 2010		192,298		$	18.42
Awarded		1,300			29.00
Vested		(79,550	)		18.06
Forfeited		(9,000	)		17.36
Nonvested as of September 30, 2011		105,048		$	18.92