Accounts Receivable Sale Program (Narrative) (Details) - USD ($) $ in Millions	3 Months Ended	6 Months Ended
Jun. 30, 2017	Jun. 30, 2017
Receivables [Abstract]
Maximum Limit Accounts Receivable Sale Program		$ 40.0
Trade Accounts Receivable Sold	$ 40.0	65.0
Amount Received From Trade Accounts Receivable Sold To Third Party	$ 39.9	$ 64.9

Accounts receivable program with third party maximum amount at any time that can be sold.

No definition available.

Name:	bhe_MaximumLimitAccountsReceivableSaleProgram
Namespace Prefix:	bhe_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration