Stock Incentive Plans (Details 2) - Restricted Stock Units [Member]	6 Months Ended
	Jun. 30, 2017 $ / shares shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares available for grant, Beginning balance	243,218
Shares available for grant, Granted	(65,261)
Shares available for grant, Exercised/issued
Shares available for grant, Cancelled/forfeited	87,419
Shares available for grant, Ending balance	265,376
Number of options outstanding, Beginning balance	253,541
Number of options outstanding, Granted
Number of options outstanding, Exercised/issued
Number of options outstanding, Cancelled/forfeited	(97,779)
Number of options outstanding, Ending balance	155,762
Weighted - average option exercise price, Beginning balance | $ / shares	$ 37.30
Weighted - average option exercise price, Granted | $ / shares
Weighted - average option exercise price, Exercised/issued | $ / shares
Weighted - average option exercise price, Cancelled/forfeited | $ / shares	34.75
Weighted - average option exercise price, Ending balance | $ / shares	$ 38.07
Number of restricted stock and board shares issued, Beginning balance	76,483
Number of restricted stock and board shares issued, Granted	6,162
Number of restricted stock and board shares issued, Exercised/issued
Number of restricted stock and board shares issued, Cancelled/forfeited
Number of restricted stock and board shares issued, Ending balance	82,645
Number of restricted stock units outstanding, Beginning balance	12,584
Number of restricted stock units outstanding, Granted	59,098
Number of restricted stock units outstanding, Exercised/issued	(49,156)
Number of restricted stock units outstanding, Cancelled/forfeited
Number of restricted stock units outstanding, Ending balance	22,526