Stockholders' Equity (Details 1) - Stock option plans [Member]	6 Months Ended
	Jun. 30, 2019 $ / shares shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of Shares, Non-vested stock options as of January 1, 2019 | shares	334,000
Non-vested stock options as of June 30, 2019 | shares	303,000
Number of Shares, Stock options granted during the six-month period ended June 30, 2019 | shares	20,000
Number of Shares, Stock options that vested during the six-month period ended June 30, 2019 | shares	31,000
Number of Shares, Stock options that were forfeited during the six-month period ended June 30, 2019 | shares	20,000
Weighted Average Fair Value at Grant Date, Non-vested stock options as of January 1, 2019	$ 3.63
Weighted Average Fair Value at Grant Date, Non-vested stock options as of June 30, 2019	3.60
Weighted Average Fair Value at Grant Date, Stock options granted during the six-month period ended June 30, 2019	3.31
Weighted Average Fair Value at Grant Date, Stock options that vested during the six-month period ended June 30, 2019	4.02
Weighted Average Fair Value at Grant Date, Stock options that were forfeited during the six-month period ended June 30, 2019	3.13
Weighted Average Exercise Price, Non-vested stock options as of January 1, 2019	6.64
Weighted Average Exercise Price, Non-vested stock options as of June 30, 2019	7.25
Weighted Average Exercise Price, Stock options granted during the six-month period ended June 30, 2019	7.03
Weighted Average Exercise Price, Stock options that vested during the six-month period ended June 30, 2019	6.74
Weighted Average Exercise Price, Stock options that were forfeited during the six-month period ended June 30, 2019	$ 5.65