Long-Term Debt (Detail Textuals 2) $ in Millions	Dec. 31, 2018 USD ($)
Line of Credit Facility [Line Items]
Letter of credit outstanding amount	$ 105.5
Uncommitted letter of credit facility
Line of Credit Facility [Line Items]
Letter of credit outstanding amount	$ 19.5

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

No definition available.

Name:	us-gaap_LineOfCreditFacilityLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration