Stock Based Compensation And Other Benefit Plans (Tables)

12 Months Ended

Dec. 31, 2011

Stock Based Compensation and Other Benefit Plans [Abstract]

Summary of stock option activity

	Shares			Weighted- Average Exercise Price		Weighted- Average Remaining Contractual Life (Years)		Aggregate Intrinsic Value
Outstanding at beginning of period		3,901,232		$	5.44
Granted		725,643			9.13
Exercised		(671,871	)		5.34
Expired or cancelled		(333,991	)		5.23
Outstanding at end of period		3,621,013		$	6.21		6.11	$	11,908,247
Vested or expected to vest at end of period		3,554,364		$	6.19	$	6.07	$	11,762,252
Options exercisable at end of period		2,079,337		$	6.54		4.62	$	6,162,396

Assumptions used in Black - Scholes option valuation model

	Year Ended December 31,
	2011			2010			2009
Risk-free interest rate		1.59	%		1.99	%		2.93	%
Expected life of the option in years		5.22			5.22			5.22
Expected volatility		63.1	%		62.5	%		62.5	%
Dividend yield		—			—			—

Summary of information about the weighted-average exercise price and the weighted-average grant date fair value of stock options granted

	Year Ended December 31,
	2011		2010		2009
Weighted-average exercise price of the stock on the date of grant	$	9.13	$	5.61	$	3.31
Weighted-average grant date fair value on the date of grant	$	5.00	$	3.08	$	1.85

Summary of activity for outstanding cash-settled stock appreciation rights

	Rights
Outstanding at the beginning of the period		545,800
Exercised		(210,200	)
Forfeited		(22,934	)
Outstanding at the end of the period		312,666
Exercisable at end of period		312,666

Summary of activity for outstanding performance-based restricted stock units

Nonvested Shares (Performance-Based)	Shares			Weighted- Average Grant Date Fair Value
Outstanding at beginning of the period		708,280		$	4.88
Forfeited		(327,050	)		6.71
Outstanding at the end of the period		381,230		$	3.31

Summary of activity for outstanding cash-settled performance-based restricted stock units

Nonvested Shares (Cash-Settled Performance Based)	Shares
Outstanding at beginning of the period		260,000
Forfeited		(260,000	)
Outstanding at the end of the period		—

Summary of activity for outstanding time-vesting restricted stock awards

Nonvested Shares (Time-Vesting)	Shares			Weighted- Average Grant Date Fair Value
Nonvested at January 1, 2011		847,693		$	6.00
Granted		792,542			9.04
Vested		(365,736	)		6.14
Forfeited		(108,770	)		7.06
Nonvested at December 31, 2011		1,165,729		$	7.92