Long-Term Debt (Schedule of ROW Credit Facilities) (Details) (Rest of World ("ROW") Credit Facilities [Member], USD $) In Millions, unless otherwise specified	6 Months Ended	12 Months Ended
Jul. 01, 2011	Dec. 31, 2010
Rest of World ("ROW") Credit Facilities [Member]
Outstanding borrowings	$ 171.4	$ 79.1
Undrawn availability	$ 248.5	$ 279.3
Interest rate - weighted average	3.30%	3.40%
Maturity date	Various	Various

- Definition

Reflects the calculation as of the balance sheet date of the average interest rate weighted by the amount of debt outstanding by type or by instrument at that time.

+ Details

Name:	bgc_DebtWeightedAverageInterestRate
Namespace Prefix:	bgc
Data Type:	us-types:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Line of credit facility maturity date.

+ Details

Name:	bgc_LineOfCreditFacilityMaturityDate
Namespace Prefix:	bgc
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount borrowed under the credit facility as of the balance-sheet date.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Section 02
-Paragraph 19, 22
-Article 5

+ Details

Name:	us-gaap_LineOfCreditFacilityAmountOutstanding
Namespace Prefix:	us-gaap
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount of borrowing capacity currently available under the credit facility (current borrowing capacity less the amount of borrowings outstanding).

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Section 02
-Paragraph 19, 22
-Article 5

+ Details

Name:	us-gaap_LineOfCreditFacilityRemainingBorrowingCapacity
Namespace Prefix:	us-gaap
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant