Income Taxes (Income Tax Provision (Benefit) Reconciliation) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Income Tax Disclosure [Abstract]
Tax provision at statutory U.S. federal income tax rate	$ (3,040)	$ 3,214	$ 10,611
State income tax — net of federal income tax benefit	(676)	(2,726)	500
Worthless stock deduction		(9,631)
Charitable contributions	(469)	(1,764)
Adjustment to deferred tax depreciation	1,135	(1,670)
Change in deferred state tax rate		(811)
Research and development tax credits	(286)	(691)
Purchase price adjustment	393	(393)
Foreign income tax provision (benefit)			238
Changes in unrecognized tax benefits	(186)	127	(196)
Changes in valuation allowance	270	2,246	(500)
Other	362	569	(193)
Income tax provision (benefit)	$ (2,497)	$ (11,530)	$ 10,460