Income Taxes (Details Textuals) (USD $)	3 Months Ended	6 Months Ended
Jun. 30, 2012	Jun. 30, 2012	Jun. 30, 2011
Income Tax Contingency [Line Items]
Income tax liability	$ 4,083,000	$ 4,083,000
Gain On Sale Of Patent Assets Before Tax		72,800,000
Tax benefits from such stock-based awards	12,684,000	12,684,000
Income tax expense	16,768,000	16,770,000	2,000
Federal
Income Tax Contingency [Line Items]
Income tax liability	3,100,000	3,100,000
State
Income Tax Contingency [Line Items]
Income tax liability	$ 1,000,000	$ 1,000,000

Carrying amount as of the balance sheet date of the unpaid sum of the known and estimated amounts payable to satisfy all currently due domestic and foreign income tax obligations.

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Tax benefit associated with any equity-based compensation plan other than an employee stock ownership plan (ESOP). The tax benefit results from the deduction by the entity on its tax return for an award of stock that exceeds the cumulative compensation cost for common stock or preferred stock recognized for financial reporting. Includes any resulting tax benefit that exceeds the previously recognized deferred tax asset (excess tax benefits).

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- Definition

The sum of the current income tax expense or benefit and the deferred income tax expense or benefit pertaining to continuing operations.

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