CONSOLIDATED STATEMENTS OF CASH FLOWS (USD $)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2011 Equities	Dec. 31, 2012 Investment Banking	Dec. 31, 2011 Investment Banking	Dec. 31, 2012 MBS & Rates
Cash flows from operating activities:
Net loss	$ (77,690,000)	$ (82,124,000)	$ (20,621,000)
Adjustments to reconcile net loss to net cash provided by (used in) operating activities:
Deferred income taxes	29,144,000	1,394,000	(17,444,000)
Impairment of goodwill and intangible assets	21,096,000	80,244,000		14,311,000	3,732,000	80,244,000	17,364,000
Amortization of stock-based compensation	6,800,000	15,074,000	54,338,000
Clawback of stock-based compensation awards subject to non-competition provisions	(2,630,000)
Investment gains, net	(1,233,000)	(2,996,000)	(7,000)
Depreciation and amortization	1,882,000	1,936,000	1,624,000
Amortization of intangible assets	538,000	2,099,000	3,698,000
Gain from bargain purchase - ClearPoint Funding, Inc. acquisition		(2,330,000)
Loss from extinguishment of mandatorily redeemable preferred stock			1,608,000
Loss from disposal of office equipment and leasehold improvements		316,000	419,000
Amortization of discount of mandatorily redeemable preferred stock			173,000
Amortization of debt issuance costs			125,000
Changes in operating assets and liabilities:
Cash and securities segregated for regulatory purposes	(3,388,000)	(9,512,000)
Securities purchased under agreements to resell	1,523,227,000	(1,436,743,000)	(86,484,000)
Net receivable/payable from/to related parties		861,000	(1,349,000)
Net receivable from others	2,712,000	4,019,000	(1,787,000)
Financial instruments owned, at fair value	458,479,000	(226,574,000)	(301,542,000)
Income taxes receivable/payable, net	4,099,000	(2,526,000)	(16,105,000)
Other assets	707,000	2,482,000	1,763,000
Net payable to brokers, dealers, and clearing organizations	(424,703,000)	(25,831,000)	404,021,000
Securities sold, but not yet purchased, at fair value	(52,266,000)	72,348,000	39,287,000
Securities sold under agreements to repurchase	(1,318,695,000)	1,478,081,000
Accounts payable and accrued expenses	(8,893,000)	5,868,000	1,411,000
Accrued compensation	7,925,000	(35,853,000)	(7,477,000)
Drafts payable	(2,000)	(847,000)	388,000
Net cash provided by/(used in) operating activities	167,109,000	(146,303,000)	56,039,000
Cash flows from investing activities:
Purchases of office equipment and leasehold improvements	(458,000)	(2,230,000)	(5,627,000)
Payment to former stockholders of Gleacher Partners, Inc. (Refer to Note 28)	(4,373,000)		(4,920,000)
Purchase of investments	(950,000)	(1,462,000)	(691,000)
ClearPoint acquisition - net cash acquired (Refer to Note 11)		626,000
Return of capital - investments		3,385,000	1,819,000
Payment to sellers of American Technology Holdings, Inc.			(1,382,000)
Net cash (used in)/provided by investing activities	(5,781,000)	319,000	(10,801,000)
Cash flows from financing activities:
Proceeds from secured borrowings	1,492,063,000	1,645,217,000
Repayments of secured borrowings	(1,640,766,000)	(1,475,945,000)
Purchases of treasury stock	(1,151,000)	(18,898,000)
Extinguishment of mandatorily redeemable preferred stock			(25,905,000)
Payments for employee tax withholding on stock-based compensation	(3,005,000)	(7,601,000)	(6,735,000)
Excess tax benefits related to stock-based compensation	8,000	239,000	2,702,000
Payment of expenses to purchase treasury stock	(75,000)	(257,000)
Repayment of subordinated debt	(206,000)	(108,000)	(288,000)
Net cash (used in)/provided by financing activities	(153,132,000)	142,647,000	(30,226,000)
Increase/(decrease) in cash and cash equivalents	8,196,000	(3,337,000)	15,012,000
Cash and cash equivalents at beginning of the year	36,672,000	40,009,000	24,997,000
Cash and cash equivalents at the end of the year	44,868,000	36,672,000	40,009,000
Cash paid during the year for:
Income taxes	382,000	735,000	17,016,000
Interest	$ 12,827,000	$ 11,174,000	$ 11,256,000
NON CASH INVESTING AND FINANCING ACTIVITIES
Treasury stock, net of forfeitures, for stock-based compensation exercises and vesting (in shares)	5,800,000	1,300,000	1,200,000
Issuance of common stock for stock-based compensation (in shares)	0	2,300,000	5,900,000
Shares reclaimed from escrow-Gleacher Partners, Inc. indemnification			300,000
Shares returned as excess collateral from clearing broker			100,000
Common stock issued to the former stockholders of AmTech in connection with contingent consideration arrangement (in shares)		15,000	345,000