Employee Benefit Plans (Details) (USD $)	12 Months Ended
Dec. 31, 2014	Dec. 31, 2013
Options Outstanding, Number of Options
Balance, December 31, 2011	2,430,127
Granted	0
Balance, December 31, 2012	2,265,842
Options Outstanding, Weighted Average Exercise Price
Balance, December 31, 2011 (in dollars per share)	$ 12.63
Granted (in dollars per share)	$ 0.00
Exercised (in dollars per share)	$ 10.06
Forfeited (in dollars per share)	$ 0.00
Balance, December 31, 2012 (in dollars per share)	$ 12.82
Options Exercisable, Number of Options
Number of Options	2,265,842	2,430,127
Options Exercisable, Weighted Average Exercise Price
Weighted Average Exercise Price (in dollars per share)	$ 12.82	$ 12.63
Restricted Stock, Number Of shares
Vested	0
Restricted Stock, Weighted Average Fair Value Per Restricted Stock
Vested (in dollars per share)	$ 0
Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Employee Service Share-based Compensation, Nonvested Awards, Total Compensation Cost Not yet Recognized	$ 0
Restricted Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Employee Service Share-based Compensation, Nonvested Awards, Total Compensation Cost Not yet Recognized	$ 2,500,000
Options Outstanding, Number of Options
Exercised	0
Options Outstanding, Weighted Average Exercise Price
Exercised (in dollars per share)	$ 0
Restricted Stock, Number Of shares
Balance, December 31, 2011	758,745
Granted	873,010
Vested	(619,578)
Forfeited	(12,199)
Balance, December 31, 2012	999,978
Restricted Stock, Weighted Average Fair Value Per Restricted Stock
Balance, December 31, 2011 (in dollars per share)	$ 23.89
Granted (in dollars per share)	$ 23.14
Vested (in dollars per share)	$ 22.70
Forfeited (in dollars per share)	$ 23.74
Balance, December 31, 2012 (in dollars per share)	$ 23.98
Outstanding [Member]
Options Outstanding, Number of Options
Exercised	(164,285)
Exercisable [Member]
Options Outstanding, Number of Options
Exercised	164,285

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Unrecognized cost of unvested share-based compensation awards.

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-Name Accounting Standards Codification

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The number of equity-based payment instruments, excluding stock (or unit) options, that were forfeited during the reporting period.

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Weighted average fair value as of the grant date of equity-based award plans other than stock (unit) option plans that were not exercised or put into effect as a result of the occurrence of a terminating event.

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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 weighted average fair value at grant date for nonvested equity-based awards issued 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 number of non-vested equity-based payment instruments, excluding stock (or unit) options, that validly exist and are outstanding as of the balance sheet date.

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The weighted average fair value of nonvested awards on equity-based plans excluding option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, revenue or profit achievement stock award plan) for which the employer is contingently obligated to issue equity instruments or transfer assets to an employee who has not yet satisfied service or performance criteria necessary to gain title to proceeds from the sale of the award or underlying shares or units.

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The number of equity-based payment instruments, excluding stock (or unit) options, that vested during the reporting period.

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The weighted average fair value as of grant date pertaining to an equity-based award plan other than a stock (or unit) option plan for which the grantee gained the right during the reporting period, by satisfying service and performance requirements, to receive or retain shares or units, other instruments, or cash in accordance with the terms of the arrangement.

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The number of shares into which fully or partially vested stock options outstanding as of the balance sheet date can be currently converted under the option plan.

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The weighted-average price as of the balance sheet date at which grantees can acquire the shares reserved for issuance on vested portions of options outstanding and currently exercisable under the stock option plan.

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

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No definition available.

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Number of options outstanding, including both vested and non-vested options.

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Weighted average price at which grantees can acquire the shares reserved for issuance under the stock option plan.

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Weighted average price at which option holders acquired shares when converting their stock options into shares.

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Weighted average price at which grantees could have acquired the underlying shares with respect to stock options that were terminated.

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Weighted average per share amount at which grantees can acquire shares of common stock by exercise of options.

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No definition available.

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Number of share options (or share units) exercised during the current period.

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