Income Taxes - Schedule of Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Ordinary deferred tax assets:
NOL carryforward	$ 7,204	$ 15,619
Deferred net loss on designated hedges		4,381
Stock-based compensation	1,726	1,999
Other, net	86	19
Total ordinary deferred tax assets	9,016	22,018
Ordinary deferred tax liabilities:
Deferred net gain on designated hedges	(4,443)
Net unrealized gain on designated hedges	(38,212)	(21,218)
Total ordinary deferred tax liabilities	(42,655)	(21,218)
Ordinary deferred tax liabilities, net	(33,639)
Ordinary deferred tax assets, net		800
Capital deferred tax assets:
NCL carryforward	100,624	80,895
Net unrealized loss on investments	44,535	23,431
Valuation allowance	(145,159)	(104,326)
Total deferred tax liabilities, net	$ (33,639)
Total deferred tax assets, net		$ 800