Related Party Transactions (Details) (USD $)	12 Months Ended			12 Months Ended		3 Months Ended	12 Months Ended						3 Months Ended		12 Months Ended			0 Months Ended
	Dec. 31, 2010	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010 Additional paid-in capital	Nov. 07, 2012 RangeMark	Mar. 31, 2010 AmTech	Dec. 31, 2011 AmTech	Dec. 31, 2010 AmTech	Dec. 31, 2010 AmTech Additional paid-in capital	Dec. 31, 2012 MatlinPatterson or its affiliated persons or entities	Dec. 31, 2011 MatlinPatterson or its affiliated persons or entities	Dec. 31, 2010 MatlinPatterson or its affiliated persons or entities	Dec. 31, 2010 Former stockholders of Gleacher Partners, Inc.	Sep. 30, 2010 Former stockholders of Gleacher Partners, Inc.	Dec. 31, 2012 Former stockholders of Gleacher Partners, Inc.	Dec. 31, 2011 Former stockholders of Gleacher Partners, Inc.	Dec. 31, 2010 Former stockholders of Gleacher Partners, Inc.	Nov. 07, 2012 Former owners of RangeMark RangeMark item	Dec. 31, 2012 Former owners of RangeMark RangeMark
Related Party Transactions
Investment banking revenues from related party	$ 1,947,000									$ 0	$ 0	$ 1,900,000
Aggregate purchase consideration					2,500,000													2,500,000
Number of installments in which purchase consideration is payable																		4
Reduction in indemnification claim based upon the resolution of certain tax years														800,000
Shares of common stock reclaimed from the escrow account in connection with the resolution of certain tax years	(685,000)												700,000
Amount agreed to be paid to selling parties															10,000,000
Period over which purchase consideration will be paid to selling parties															5 years
Payment of purchase consideration obligation															4,400,000	0	4,900,000
Payment to sellers of American Technology Holdings, Inc.	1,382,000							1,400,000
Number of shares of common stock issued to former stockholders						345,000	0	345,043
Settlement of contingent consideration related to the American Technology Holdings, Inc. acquisition (Refer to Note 28)	1,517,000			1,514,000					1,500,000
Amounts receivable from or payable to related parties
Receivables from related parties		1,474,000	1,337,000												1,474,000	1,337,000
Payables to related parties		2,944,000	4,939,000												594,000	4,939,000			2,350,000
Present value of remaining obligation																$ 5,000,000