Consolidated Variable Interest Entities - Additional Information (Details)	9 Months Ended
Sep. 30, 2019 USD ($) entity	Sep. 30, 2018 USD ($)	Dec. 31, 2018 entity
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Number of VIEs consolidated \| entity	5		4
Financial or other support to any VIEs \| $	$ 0	$ 0

The amount of financial or other support the reporting entity has provided (explicitly or implicitly) to the Variable Interest Entity (VIE) that it was not previously contractually required to provide or that the reporting entity intends to provide, including, for example, situations in which the reporting entity assisted the VIE in obtaining another type of support.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 810
-SubTopic 10
-Section 50
-Paragraph 5A
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=118582676&loc=SL6759159-111685

Name:	us-gaap_VariableInterestEntityFinancialOrOtherSupportAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration