Securities and Equity Investments - Enertech FV (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Sep. 30, 2018
Investments, Debt and Equity Securities [Abstract]
Carrying value	$ 558	$ 558

Amount, after adjustment, of cost-method investment. Adjustments include, but are not limited to, dividends received in excess of earnings after date of investment that are considered a return of investment and other than temporary impairments.

No definition available.

Name:	us-gaap_CostMethodInvestments
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant