Income Taxes (Details Textual) - USD ($)	3 Months Ended								12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Income Tax [Line Items]
Deferred Tax Assets Tax Deferred Compensation Noncurrent	$ 1,074,000				$ 2,082,000				$ 1,074,000	$ 2,082,000
Income Tax Expense (Benefit)	2,450,000	$ 2,599,000	$ 3,141,000	$ 1,450,000	$ 3,050,000	$ 2,180,000	$ 3,193,000	$ 1,627,000	9,640,000	10,050,000	$ 9,992,000
Income Tax Examination, Penalties and Interest Accrued	$ 0								0
Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Value									893,000
Adjustments Related to Tax Withholding for Share-based Compensation									$ 360,000	360,000
Share-based Compensation Arrangement by Share-based Payment Award, Options, Expirations in Period									59,000
Stock Option [Member]
Income Tax [Line Items]
Income Tax Expense (Benefit)									$ 230,000	$ 10,000	$ (9,200)