Related Party Transactions (Details) (USD $)			0 Months Ended	9 Months Ended	12 Months Ended				3 Months Ended		9 Months Ended
	Sep. 30, 2013	Dec. 31, 2012	Nov. 07, 2012 RangeMark item	Sep. 30, 2013 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.	Dec. 31, 2012 Former owners of RangeMark	Sep. 30, 2013 MatlinPatterson or its affiliated persons or entities item	Sep. 30, 2013 Capstone	Sep. 30, 2013 Capstone
Related Party Transactions
Expenses incurred in related party transaction										$ 900,000	$ 1,600,000
Aggregate purchase consideration			2,500,000
Number of installments in which purchase consideration is payable			4
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
Amounts receivable from or payable to related parties
Receivables from related parties	1,546,000	1,474,000		1,546,000	1,474,000
Payables to related parties	1,025,000	2,944,000		594,000	594,000			2,350,000		431,000	431,000
Expense reimbursement of MatlinPatterson									$ 1,100,000
Number of members in Audit Committee not standing for re-election									4