Variable Interest Entities - Additional Information (Details) $ in Millions	Sep. 30, 2019 USD ($)
PEGH 2 Investment \| Variable Interest Entity, Not Primary Beneficiary
Variable Interest Entity [Line Items]
Carrying value of unconsolidated investment	$ 123

Net carrying amount of the assets and liabilities in the reporting entity's statement of financial position that relate to the reporting entity's variable interest in the Variable Interest Entity (VIE), when the reporting entity is not the VIE's primary beneficiary.

No definition available.

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