Employee Benefit Plans - Executive Incentive Retirement Plan (Details) - Executive Management $ in Thousands	9 Months Ended
Sep. 30, 2021 USD ($)
Deferred Compensation Arrangement with Individual, Postretirement Benefits
Deferred compensation arrangement, option to elect to defer fees and bonuses, percentage	100.00%
Other Postretirement Benefits Plan
Deferred Compensation Arrangement with Individual, Postretirement Benefits
Deferred compensation arrangement, option to elect to defer fees and bonuses, percentage	7.50%
Accrued employee benefits	$ 84

Carrying value as of the balance sheet date of obligations, excluding pension and other postretirement benefits, incurred through that date and payable for perquisites provided to employees pertaining to services received from them.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03.15(a))
-URI http://asc.fasb.org/extlink&oid=120400017&loc=d3e572229-122910

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03.15(5))
-URI http://asc.fasb.org/extlink&oid=120398452&loc=d3e534808-122878

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