Equity Incentive Awards (Details 3) - $ / shares	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Share-based Compensation Arrangement by Share-based Payment Award
Share-based Compensation Arrangement by Share-based Payment Award, Stock Bonus and Restricted Stock, Grants in Period	10,248	11,456	21,360
Share-based Compensation Arrangement by Share-based Payment Award, Stock Bonus and Restricted Stock to Consultants, Grants in Period, Weighted Average Grant Date Fair Value	$ 15.61	$ 13.96	$ 7.49