Stock-Based Compensation (Details) (USD $) In Thousands, except Share data, unless otherwise specified	6 Months Ended
Jun. 30, 2012
Stock-Based Compensation Arrangement Rollforward
Restricted stock used for tax withholding	(643)
Phantom Shares \| Phantom Stock Plan
Stock-Based Compensation [Line Items]
Maximum percentage of fair market value of the Company available for share-based awards	2.00%
Maximum individual award as a percentage of shares available for award	5.00%
Days from vesting date to cash settlement	120 days
Stock-Based Compensation Arrangement Rollforward
Unvested and outstanding at beginning of period	16.37
Unvested and outstanding at beginning of period (in shares)	125,768
Granted	0.00
Granted (in shares)	0
Vested	14.35
Vested (in shares)	(23,188)
Vest Date Fair Value	384
Forfeited	17.32
Forfeited (in shares)	(9,709)
Unvested and outstanding at end of period	16.78
Unvested and outstanding at end of period (in shares)	92,871
Phantom Shares \| Time Vested \| Phantom Stock Plan
Stock-Based Compensation [Line Items]
Vesting period	5 years
Restricted Stock Units (RSU) \| Non-Officer Restricted Stock Unit Plan
Stock-Based Compensation [Line Items]
Maximum percentage of fair market value of the Company available for share-based awards	2.00%
Days from vesting date to cash settlement	120 days
Stock-Based Compensation Arrangement Rollforward
Unvested and outstanding at beginning of period	0.00
Unvested and outstanding at beginning of period (in shares)	0
Granted	17.84
Granted (in shares)	151,170
Vested	0.00
Vested (in shares)	0
Forfeited	17.84
Forfeited (in shares)	(10,160)
Unvested and outstanding at end of period	17.84
Unvested and outstanding at end of period (in shares)	141,010
Phantom Stock and RSU \| Phantom Stock Plan And Restricted Stock Unit Plan
Stock-Based Compensation Arrangement Rollforward
Estimated fair value per share at end of period	12.57
Aggregate intrinsic value of unvested awards outstanding	2,940
Restricted Stock \| 2010 Equity Incentive Plan \| Common Class A
Stock-Based Compensation Arrangement Rollforward
Shares reserved for issuance under the 2010 Plan	86,301
Restricted stock used for tax withholding	(643)
Shares expected to be repurchased during the next twelve months	1,000
Restricted Stock \| Time Vested \| 2010 Equity Incentive Plan \| Common Class A
Stock-Based Compensation Arrangement Rollforward
Unvested and outstanding at beginning of period	680.74
Unvested and outstanding at beginning of period (in shares)	11,585
Granted	747.08
Granted (in shares)	125
Vested	681.67
Vested (in shares)	(2,498)
Vest Date Fair Value	1,866
Forfeited	685.50
Forfeited (in shares)	(396)
Unvested and outstanding at end of period	681.20
Unvested and outstanding at end of period (in shares)	8,816
Estimated fair value per share at end of period	563.30
Aggregate intrinsic value of unvested awards outstanding	4,966
Restricted Stock \| Performance Vested \| 2010 Equity Incentive Plan \| Common Class A
Stock-Based Compensation Arrangement Rollforward
Unvested and outstanding at beginning of period	298.15
Unvested and outstanding at beginning of period (in shares)	53,098
Granted	394.00
Granted (in shares)	278
Vested	0.00
Vested (in shares)	0
Forfeited	302.13
Forfeited (in shares)	(1,499)
Unvested and outstanding at end of period	298.55
Unvested and outstanding at end of period (in shares)	51,877
Maximum \| Restricted Stock Units (RSU)
Stock-Based Compensation [Line Items]
Vesting period	3 years
Maximum \| Restricted Stock \| Time Vested
Stock-Based Compensation [Line Items]
Vesting period	5 years

Maximum Individual Award, Percentage Of The Total Shares Available For Award Under Plan

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Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Nonvested Aggregate Intrinsic Value

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Share-Based Compensation Arrangement By Share-Based Payment Award, Period From Vesting Date Before Award Is Cash Settled

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Period 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, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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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).

+ References

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The intrinsic 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, as calculated by applying the disclosed pricing methodology.

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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.

+ References

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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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- Definition

The total fair value of equity-based awards 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 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 maximum number of shares (or other type of equity) originally approved (usually by shareholders and board of directors), net of any subsequent amendments and adjustments, for awards under the equity-based compensation plan. As stock or unit options and equity instruments other than options are awarded to participants, the shares or units remain authorized and become reserved for issuance under outstanding awards (not necessarily vested).

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- Definition

Maximum number of shares that may be issued in accordance with the plan as a proportion of outstanding capital stock.

+ References

No definition available.

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- Definition

An entity expecting to repurchase shares in the following period, generally discloses an estimate of the amount or range of shares to be repurchased.

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- Definition

For net-share settlement of share-based awards when the employer settles employees' income tax withholding obligations, this element represents the number of shares the employees use to repay the employer.

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No definition available.

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