Organization And Nature Of Business	6 Months Ended
Jun. 30, 2014
Organization And Nature Of Business [Abstract]
Organization And Nature Of Business	1. Organization and Nature of Business Interactive Brokers Group, Inc. (“IBG, Inc.” or the “Company”) is a Delaware holding company whose primary asset is its ownership of approximately 14.1% of the membership interests of IBG LLC, which, in turn, owns operating subsidiaries (collectively, “IBG LLC” or the “Group”). The accompanying condensed consolidated financial statements of IBG, Inc. reflect the consolidation of IBG, Inc.’s investment in IBG LLC for all periods presented (Note 4). IBG LLC is an automated global electronic broker and market maker specializing in routing orders and processing trades in securities, futures and foreign exchange instruments. IBG LLC is a Connecticut limited liability company that conducts its business through its operating subsidiaries (collectively called the “Operating Companies”): Interactive Brokers LLC (“IB LLC”) and subsidiary (Interactive Brokers Corp.), Interactive Brokers Canada Inc. (“IBC”), Interactive Brokers (U.K.) Limited (“IBUK”), Interactive Brokers Securities Japan, Inc. (“IBSJ”), Interactive Brokers (India) Private Limited (“IBI”), Timber Hill LLC (“TH LLC”), Timber Hill Europe AG and subsidiary (collectively “THE”), Timber Hill Securities Hong Kong Limited (“THSHK”), Timber Hill Australia Pty Limited (“THA”), Timber Hill Canada Company (“THC”), Interactive Brokers Financial Products S.A. (“IBFP”), Interactive Brokers Hungary KFT (“IBH”), IB Exchange Corp. (“IBEC”), Interactive Brokers Software Services Estonia OU (“IBEST”) and Interactive Brokers Software Services Russia (“IBRUS”). IBG, Inc. operates in two business segments, electronic brokerage and market making. IBG, Inc. conducts its electronic brokerage business through certain Interactive Brokers subsidiaries, which provide electronic execution and clearing services to customers worldwide. The Company conducts its market making business principally through its Timber Hill subsidiaries on the world’s leading exchanges and market centers, primarily in exchange‑traded equities, equity options and equity‑index options and futures. Certain of the Operating Companies are members of various securities and commodities exchanges in North America, Europe and the Asia/Pacific region and are subject to regulatory capital and other requirements (Note 13). IB LLC, IBUK, IBC, IBI and IBSJ carry securities accounts for customers or perform custodial functions relating to customer securities.

1. Organization and Nature of Business

Interactive Brokers Group, Inc. (“IBG, Inc.” or the “Company”) is a Delaware holding company whose primary asset is its ownership of approximately 14.1% of the membership interests of IBG LLC, which, in turn, owns operating subsidiaries (collectively, “IBG LLC” or the “Group”). The accompanying condensed consolidated financial statements of IBG, Inc. reflect the consolidation of IBG, Inc.’s investment in IBG LLC for all periods presented (Note 4). IBG LLC is an automated global electronic broker and market maker specializing in routing orders and processing trades in securities, futures and foreign exchange instruments.

IBG LLC is a Connecticut limited liability company that conducts its business through its operating subsidiaries (collectively called the “Operating Companies”): Interactive Brokers LLC (“IB LLC”) and subsidiary (Interactive Brokers Corp.), Interactive Brokers Canada Inc. (“IBC”), Interactive Brokers (U.K.) Limited (“IBUK”), Interactive Brokers Securities Japan, Inc. (“IBSJ”), Interactive Brokers (India) Private Limited (“IBI”), Timber Hill LLC (“TH LLC”), Timber Hill Europe AG and subsidiary (collectively “THE”), Timber Hill Securities Hong Kong Limited (“THSHK”), Timber Hill Australia Pty Limited (“THA”), Timber Hill Canada Company (“THC”), Interactive Brokers Financial Products S.A. (“IBFP”), Interactive Brokers Hungary KFT (“IBH”), IB Exchange Corp. (“IBEC”), Interactive Brokers Software Services Estonia OU (“IBEST”) and Interactive Brokers Software Services Russia (“IBRUS”).

IBG, Inc. operates in two business segments, electronic brokerage and market making. IBG, Inc. conducts its electronic brokerage business through certain Interactive Brokers subsidiaries, which provide electronic execution and clearing services to customers worldwide. The Company conducts its market making business principally through its Timber Hill subsidiaries on the world’s leading exchanges and market centers, primarily in exchange‑traded equities, equity options and equity‑index options and futures.

Certain of the Operating Companies are members of various securities and commodities exchanges in North America, Europe and the Asia/Pacific region and are subject to regulatory capital and other requirements (Note 13). IB LLC, IBUK, IBC, IBI and IBSJ carry securities accounts for customers or perform custodial functions relating to customer securities.