Commitments and Contingent Liabilities - Additional Information (Details) - USD ($) $ in Millions	Mar. 31, 2020	Dec. 31, 2019
Commitments And Contingencies Disclosure [Abstract]
Unfunded commitments - LLC Investments	$ 39.7	$ 44.9

Unused amount of commitments to extend credit to customers.

No definition available.

Name:	us-gaap_UnusedCommitmentsToExtendCredit
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant