Related Party Transactions - Additional Information (Details) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2018	Dec. 31, 2017
Related Party Transaction [Line Items]
Receivable balance due from a direct wholly-owned subsidiary	$ 10,118	$ 10,129
Joint Venture
Related Party Transaction [Line Items]
Asset Management Fees	113
Receivable balance due from joint venture	$ 38

For an unclassified balance sheet, amount of receivables due from an entity that is affiliated with the reporting entity by means of direct or indirect ownership.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant