Schedule of 2003 Stock Option and Appreciation Rights Plan (Details) - shares	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Options outstanding, beginning of year	5,169,200	2,175,000
Options forfeited	(168,750)	(205,000)
Options exercised	(10,000)	(40,000)
Options expired	0	(20,000)
Options outstanding, end of year	5,040,450	5,169,200
2003 Stock Option and Appreciation Rights Plan [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Options outstanding, beginning of year	995,000	1,170,000
Options forfeited	0	(115,000)
Options exercised	(10,000)	(40,000)
Options expired	0	(20,000)
Options outstanding, end of year	985,000	995,000