Common Stock Plans (Stock Repurchase Program) (Details) - USD ($)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Oct. 22, 2014
Equity, Class of Treasury Stock [Line Items]
Purchase and retirement of shares, value		$ 14,913,000
Common Stock
Equity, Class of Treasury Stock [Line Items]
Stock repurchase program, authorized amount				$ 3,600,000
Stock repurchase program, remaining authorized repurchase amount	$ 3,373,161
Shares acquired in connection with stock compensation plans	73,126	32,768	14,766
Common Stock
Equity, Class of Treasury Stock [Line Items]
Purchase and retirement of shares, shares	0	226,839	0
Purchase and retirement of shares, value		$ 2,000