Limited Partnership Interests in BGC Holdings - Additional Information (Detail)	3 Months Ended	12 Months Ended
Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2013 PartnershipUnit
Noncontrolling Interest [Abstract]
Number of operating partnerships					2
Payout period for post-termination awards					4 equal yearly installment
Percentage to preferred units	0.6875%	0.6875%	0.6875%	0.6875%	2.75%

Percentage of net profits of consolidated subsidiary allocated to preferred units.

No definition available.

Name:	bgcp_PercentageOfPreferredPartnershipUnitsAwarded
Namespace Prefix:	bgcp_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration