Income Taxes (Details Textual) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Pre-tax income from U.S. jurisdiction	$ 16,600,000	$ 16,900,000	$ 28,000,000
Pre-tax income from foreign jurisdictions	100,000	2,300,000	300,000
Deferred Tax Assets, Net, Current	24,300,000
Deferred Tax Assets, Valuation Allowance	12,229,000	8,999,000
Liability for Uncertain Tax Positions, Current	7,600,000
Net amount, reduced for the federal effects of potential state tax exposures	6,000,000
Net amount, favorably affect the company's tax provision in future periods	3,500,000
Increase in deferred tax assets, uncertain tax positions	2,500,000
Liability for uncertain tax positions in long term taxes payable	3,511,000	3,575,000
Unrecognized Tax Benefits, Recognized in Current Period from Lapse of Statute of Limitations	4,900,000
Income Tax Examination, Interest Accrued	300,000	300,000
State and Local Jurisdiction [Member]
Deferred Tax Assets, Tax Credit Carryforwards, Research	22,100,000
Current Income Taxes Payable [Member]
Income Tax Examination, Interest Accrued	55,000
Long-Term Income Taxes Payable [Member]
Income Tax Examination, Interest Accrued	$ 3,500,000