Schedule of 2003 Stock Option and Appreciation Rights Plan (Details) - shares	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Options outstanding, beginning of year	5,040,450	5,169,200
Options exercised	(173,130)	(10,000)
Options expired	(1,016,870)	0
Options forfeited	(73,050)	(168,750)
Options outstanding, end of year	4,303,900	5,040,450
2003 Stock Option and Appreciation Rights Plan [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Options outstanding, beginning of year	985,000	995,000
Options exercised	0	(10,000)
Options expired	(660,000)	0
Options forfeited	(15,000)	0
Options outstanding, end of year	310,000	985,000