Derivatives (Derivatives - Narrative) (Details) - USD ($) $ in Millions	Sep. 30, 2025	Dec. 31, 2024
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivative AOCI associated with Cash Flow Hedges Pre Tax	$ 241	$ 460

Derivative AOCI associated with Cash Flow Hedges Pre Tax

No definition available.

Name:	bhl_DerivativeAOCIAssociatedWithCashFlowHedgesPreTax
Namespace Prefix:	bhl_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant