Equity (Return of Capital - Narrative) (Details) - USD ($) $ in Millions		8 Months Ended
Feb. 24, 2016	Aug. 31, 2014
Capital Contribution
Capital contribution	$ 1,500	$ 231

Change in additional paid in capital as a result of a capital contribution, including transfers of ownership.

No definition available.

Name:	bhl_AdjustmentsToAdditionalPaidInCapitalCapitalContribution
Namespace Prefix:	bhl_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration