Income Taxes (Income Tax Rate Reconciliation) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Income Tax Disclosure [Abstract]
U.S. federal income tax rate	35.00%	35.00%	35.00%
Income Tax Expense (Benefit), Continuing Operations, Income Tax Reconciliation [Abstract]
United States federal tax expense (benefit) at statutory rate	$ (24,687)	$ (18,930)	$ 20,076
State taxes, net of United States federal tax expense (benefit)	(1,083)	(841)	(1,098)
Change in valuation allowance	27,759	25,046	2,136
Non-deductible stock compensation	270	415	341
Impact of non-U.S. jurisdictional tax rate difference	529	487	313
Research and development tax credit	(325)	(1,632)	(1,923)
Increase (reversal) of unrecognized tax benefits	(901)	671	(7,826)
Non-U.S. withholding tax	393	1,805	471
Other	(675)	(2,118)	28
Total income tax expense (benefit)	$ 1,280us-gaap_IncomeTaxExpenseBenefit	$ 4,903us-gaap_IncomeTaxExpenseBenefit	$ 12,518us-gaap_IncomeTaxExpenseBenefit

Income Tax Reconciliation, Foreign Tax Withholding

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Percentage of domestic federal statutory tax rate applicable to pretax income (loss).

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Amount of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations.

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Amount of the difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying the domestic federal statutory income tax rates to pretax income (loss) from continuing operations attributable to increase (decrease) in the valuation allowance for deferred tax assets.

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