XML 79 R64.htm IDEA: XBRL DOCUMENT
v2.4.0.6

Major Customers (Narrative) (Details) (USD $) In Millions, unless otherwise specified | 12 Months Ended
--- | ---
Dec. 31, 2011 | Dec. 31, 2010 | Dec. 31, 2009
Revenue, Major Customer [Line Items] |  |  |
Sales to largest customers (Percentage) | 53.00% | 47.00% | 52.00%
Sales to our largest customers |  | $ 300.9 |
Sales To Ten Largest Customers [Member] |  |  |
Revenue, Major Customer [Line Items] |  |  |
Number of customers | 10 |  |
Sales to Two Of Largest Customers [Member] |  |  |
Revenue, Major Customer [Line Items] |  |  |
Number of customers |  | 2 |

X
- Definition Number of largest customers accounted for portion of revenue + References No definition available. + Details
Name: | bhe_NumberOfLargestCustomersAccountedForPortionOfRevenue
Namespace Prefix: | bhe_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | duration

X
- Definition Percentage of revenue accounted by major customers + References No definition available. + Details
Name: | bhe_PercentageOfRevenueAccountedByMajorCustomers
Namespace Prefix: | bhe_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Sales to major customers + References No definition available. + Details
Name: | bhe_SalesToMajorCustomers
Namespace Prefix: | bhe_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Details
Name: | us-gaap_EntityWideRevenueMajorCustomerLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration