Derivative Instruments - Credit Risk and Credit-Risk-Related Contingent Feature (Details)	Sep. 30, 2019 institution
Moody's, A1 Rating
Derivative [Line Items]
Number of financial institutions company does transactions with	1

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