Income Taxes (Narrative) (Details) - USD ($)	3 Months Ended		6 Months Ended
	Sep. 30, 2018	Dec. 31, 2017	Dec. 31, 2017
Income Tax Disclosure [Line Items]
Federal statutory corporate tax rate	21.00%
Re-measurement of U.S. deferred tax assets and related valuation allowance	$ 0
Alternative minimum tax carryforward, recognition period	4 years
Alternative minimum tax repeal, benefit		$ 279,000
Transition tax rate, cash and cash equivalents	15.50%
Transition tax rate, other than cash and cash equivalents	8.00%
Transition tax payment period	8 years
Maximum [Member]
Income Tax Disclosure [Line Items]
Federal statutory corporate tax rate			35.00%