Stock Compensation Plans - Tax benefits realized (Details) $ in Thousands	6 Months Ended
Jun. 30, 2021 USD ($)
Share-Based Payment Arrangement [Abstract]
Proceeds of options exercised	$ 8
Intrinsic value of options exercised	$ 11

Amount of cash inflow from exercise of option under share-based payment arrangement.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2A
-Subparagraph (a)
-URI https://asc.fasb.org/extlink&oid=128089324&loc=SL79508275-113901

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 14
-Subparagraph (a)
-URI https://asc.fasb.org/extlink&oid=126954810&loc=d3e3255-108585

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