Related Party Transactions (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2017
Related Party Transaction [Line Items]
Balance with Fund Manager			$ 14,842
Investment income generated from mutual funds	$ 183	$ 21
Percentage of stockholders controlling a related party	10.00%	10.00%
Maximum [Member]
Related Party Transaction [Line Items]
Fund management fee percent	0.25%
Other Income [Member]
Related Party Transaction [Line Items]
Investment income generated from mutual funds	$ 200
Marketable Securities [Member]
Related Party Transaction [Line Items]
Balance with Fund Manager	$ 16,251		3,792
Cash and Cash Equivalents [Member]
Related Party Transaction [Line Items]
Balance with Fund Manager			$ 11,050