Revenue from Contracts with Customers - Narrative (Details) $ in Thousands	12 Months Ended
Dec. 31, 2018 USD ($) subsidiary	Dec. 31, 2017 USD ($)
Revenue from Contract with Customer [Abstract]
Number of wealth management subsidiaries \| subsidiary	4
Revenue recognized from contract liability balance \| $	$ 369	$ 359

Amount of revenue recognized that was previously included in balance of obligation to transfer good or service to customer for which consideration from customer has been received or is due.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
-Paragraph 8
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=109196051&loc=SL49130549-203045

Name:	us-gaap_ContractWithCustomerLiabilityRevenueRecognized
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration