Liquidity (Narrative) (Details) - USD ($)	1 Months Ended
	Jul. 31, 2018	Jun. 30, 2018	Dec. 31, 2017	Jun. 30, 2017	Dec. 31, 2016
Cash and cash equivalents		$ 5,798,000	$ 5,132,000	$ 8,962,000	$ 5,711,000
Subsequent Event [Member] | Australian Taxation Office [Member]
Tax rebates received	$ 1,200,000