Income Taxes (Narrative) (Details) $ in Thousands	3 Months Ended	12 Months Ended
	Dec. 31, 2017 USD ($)	Dec. 31, 2018 USD ($)	Dec. 31, 2017 USD ($) item	Sep. 30, 2018 USD ($)	Jun. 30, 2018 USD ($)
Income Tax [Line Items]
Income tax benefit	$ (6,521)	$ 565	$ 6,260
Employer contributions			$ 20,000
Number of properties sold | item			3
U.S. corporate income tax rate		21.00%	35.00%
Tax Cuts and Jobs Act of 2017, Change in Tax Rate, Deferred tax asset, income tax expense		$ (3,570)
Income taxes paid, net of refunds		(6,404)	$ 583
Tax, refund received				$ 4,095	$ 3,210
Federal net operating loss carryforward	$ 4,260	5,541	4,260
Other Deferred Tax Assets [Member]
Income Tax [Line Items]
Changes in valuation allowance		$ 876	$ 1,095