Post-Retirement Benefit Plans (Details Textual) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Retirement Benefits [Abstract]
Defined contribution plan, increase (decrease) in cost recognized	$ 288	$ 356	$ 606

Amount of increase (decrease) in cost for defined contribution plan.

No definition available.

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