Share Repurchase Program (Details)	6 Months Ended
	Jun. 30, 2018 USD ($) $ / shares shares
Share Repurchase Program [Abstract]
Stock Repurchase Program, Authorized Amount	$ 50,000,000
Purchase of treasury stock, shares | shares	287,257
Treasury Stock Acquired, Average Cost Per Share | $ / shares	$ 20.94
Purchase of treasury stock	$ 6,014,000
Stock Repurchase Program, Remaining Authorized Repurchase Amount	$ 44,000,000