Summary of Significant Accounting Policies (Deferred Financing Costs, Net of Accumulated Amortization) (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Deferred financing costs	$ 9,759	$ 9,775
Accumulated amortization	(3,377)	(1,908)
Deferred financing costs, net	6,382	7,867
Fixed debt arrangements
Deferred financing costs	12,804	12,675
Accumulated amortization	(2,451)	(1,039)
Deferred financing costs, net	$ 10,353	$ 11,636