Accounts Receivable Sale Program (Narrative) (Details) $ in Millions	3 Months Ended
Mar. 31, 2017 USD ($)
Receivables [Abstract]
Maximum Limit Accounts Receivable Sale Program	$ 40
Trade Accounts Receivable Sold	25
Amount Received From Trade Accounts Receivable Sold To Third Party	$ 25

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