Represents the expense recognized during the period arising from equity-based compensation arrangements (for example, shares of stock, unit, stock options or other equity instruments) with employees, directors and certain consultants qualifying for treatment as employees.

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As of the balance sheet date, the aggregate unrecognized cost of equity-based awards made to employees under equity-based compensation awards that have yet to vest.

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The weighted average period over which unrecognized compensation is expected to be recognized for equity-based compensation plans, using a decimal to express in number of years.

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The total recognized tax benefit related to compensation cost for equity-based payment arrangements recognized in income during the period.

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Disclosure of the aggregate tax benefit realized from the exercise of stock options and the conversion of similar instruments during the annual period.

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Description of the period of time over which an employee's right to exercise an award is no longer contingent on satisfaction of either a service condition, market condition or a performance condition, which may be expressed in a variety of ways (for example, in years, month and year).

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Description of award terms as to how many shares or portion of an award are no longer contingent on satisfaction of either a service condition, market condition or a performance condition, thereby giving the employee the legal right to convert the award to shares, to sell the shares, and be entitled to the cash proceeds of such sale. For example, vesting may be expressed as being 25 percent of the shares under option on each anniversary of the grant date.

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The number of grants made during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan).

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The total accumulated difference between fair values of underlying shares on dates of exercise and exercise price on options which were exercised (or share units converted) into shares during the reporting period under the plan.

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Net number of share options (or share units) granted during the period.

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The weighted average grant-date fair value of options granted during the reporting period as calculated by applying the disclosed option pricing methodology.

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Share based compensation.

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Share-Based Compensation (Details Textuals) (USD $)	3 Months Ended		9 Months Ended
Share-Based Compensation (Details Textuals) (USD $)	Sep. 30, 2011	Sep. 30, 2010	Sep. 30, 2011 Year	Sep. 30, 2010
Share-Based Compensation (Textuals) [Abstract]
Stock option granted			894,000
Estimated weighted- average grant date fair value of stock options			$ 6.00
Aggregate intrinsic value of stock options exercised	$ 194,000		$ 3,200,000
Actual tax benefit realized on options exercised	76,000		1,200,000
Nonvested common stock awards granted			1,225,046
Vesting rights of Performance-based shares			0% and 100%
Employee Stock Option [Member]
Share-Based Compensation (Textuals) [Abstract]
Weighted-average period of recognition of unrecognized compensation cost			3.7
Total unrecognized compensation cost	5,700,000		5,700,000
Compensation cost charged against income	347,000	414,000	1,000,000	2,200,000
Income tax benefit recognized during the period	136,000	161,000	407,000	872,000
Nonvested Stock Awards [Member]
Share-Based Compensation (Textuals) [Abstract]
Weighted-average period of recognition of unrecognized compensation cost			3.5
Total unrecognized compensation cost	25,800,000		25,800,000
Compensation cost charged against income	3,700,000	1,200,000	5,600,000	5,200,000
Income tax benefit recognized during the period	$ 1,500,000	$ 476,000	$ 2,200,000	$ 2,000,000
Executive Employees [Member]
Share-Based Compensation (Textuals) [Abstract]
Nonvested common stock awards granted			1,130,000
Employees [Member]
Share-Based Compensation (Textuals) [Abstract]
Nonvested common stock awards granted			1,225,046
Vesting period of shares			four equal annual installments beginning June 2012 through June 2015