Detail information of subsequent event by type. User is expected to use existing line items from elsewhere in the taxonomy as the primary line items for this disclosure, which is further associated with dimension and member elements pertaining to a subsequent event.

No definition available.

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

Subsequent Events - Additional Information (Details) - Sharyland Distribution & Transmission Services - Sharyland - Lease	1 Months Ended	9 Months Ended
	Oct. 31, 2016	Sep. 30, 2016
Subsequent Event [Line Items]
Number of lease agreements		5
Subsequent Event
Subsequent Event [Line Items]
Number of lease agreements	2
Subsequent Event \| Transmission Assets
Subsequent Event [Line Items]
Number of lease agreements	1
Subsequent Event \| Distribution Assets
Subsequent Event [Line Items]
Number of lease agreements	1