Shareholders' Equity (Details 4)	3 Months Ended
	Mar. 31, 2018 $ / shares shares
Summary of options outstanding by exercise price range
Options Outstanding, Number of Shares Underlying Options	11,472
Options Outstanding, Weighted Average Remaining Contractual Life	3 years 4 months 17 days
Options Exercisable, Number Exercisable	5,535
Stock Options [Member] | Range 1 [Member]
Summary of options outstanding by exercise price range
Options Outstanding, Exercise Price | $ / shares	$ 12.00
Options Outstanding, Number of Shares Underlying Options	222
Options Outstanding, Weighted Average Remaining Contractual Life	3 years 4 months 17 days
Options Exercisable, Number Exercisable	222
Options Exercisable, Exercise Price | $ / shares	$ 12.00
Stock Options [Member] | Range 2 [Member]
Summary of options outstanding by exercise price range
Options Outstanding, Exercise Price | $ / shares	$ 20.00
Options Outstanding, Number of Shares Underlying Options	11,250
Options Outstanding, Weighted Average Remaining Contractual Life	3 years 4 months 17 days
Options Exercisable, Number Exercisable	5,313
Options Exercisable, Exercise Price | $ / shares	$ 20.00