Summary of Significant Accounting Policies (Deferred Financing Costs, Net of Accumulated Amortization) (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Deferred financing costs	$ 9,775	$ 7,128
Accumulated amortization	(1,908)	(145)
Deferred financing costs, net	7,867	6,983
Fixed debt arrangements
Deferred financing costs	12,675	12,779
Accumulated amortization	(1,039)	(2,660)
Deferred financing costs, net	$ 11,636	$ 10,119