Summary of Significant Accounting Policies (Deferred Financing Costs, Net of Accumulated Amortization) (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Deferred financing costs	$ 9,759	$ 9,775
Accumulated amortization	(2,398)	(1,908)
Deferred financing costs, net	7,361	7,867
Fixed debt arrangements
Deferred financing costs	12,715	12,675
Accumulated amortization	(1,510)	(1,039)
Deferred financing costs, net	$ 11,205	$ 11,636