Shareholders' Equity (Stock Option Transactions) (Details) - USD ($)	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016	Dec. 31, 2016
Shareholders' Equity [Abstract]
Number of options, outstanding, beginning balance			214,500
Number of options, granted in period
Number of options, exercised in period				(15,000)
Number of options, forfeited in period	(4,000)		(4,000)
Number of options, expired in period		0
Number of options, outstanding, ending balance	210,500		210,500		214,500
Number of options, exercisable	116,495		116,495		109,495
Weighted average exercise price, outstanding, beginning of period			$ 5.96
Weighted average exercise price, options granted in period
Weighted average exercise price, options exercised in period
Weighted average exercise price, options forfeited in period			3.67
Weighted average exercise price, options expired in period
Weighted average exercise price, options exercisable	$ 6.86		6.86		$ 6.90
Weighted average exercise price, outstanding, ending of period	$ 6.00		$ 6.00		$ 5.96
Weighted average remaining contractual term (in years), options outstanding			6 years 7 months 17 days		7 years 1 month 13 days
Weighted average remaining contractual term (in years), options exercisable			5 years 1 month 10 days		5 years 5 months 19 days
Aggregate intrinsic value, options outstanding	$ 28,750		$ 28,750		$ 17,340
Aggregate intrinsic value, options exercisable	$ 17,980		$ 17,980		$ 8,880