Consolidated Statements of Financial Condition (Parenthetical) - USD ($)		Dec. 31, 2016	Dec. 31, 2015
Assets
Fixed assets, accumulated depreciation and amortization (in dollars)		$ 23,867,000	$ 29,953,000
Intangible assets, accumulated amortization (in dollars)		$ 29,418,000	$ 28,301,000
Stockholders' equity
Preferred stock, par value (in dollars per share)		$ 0.01	$ 0.01
Preferred stock, shares authorized		10,000,000	10,000,000
Preferred stock, shares issued		120,750	120,750
Preferred stock, shares outstanding		120,750	120,750
Preferred Stock, Liquidation Preference, Value		$ 120,750,000	$ 120,750,000
Common stock, shares authorized		125,000,000
Treasury Stock, Shares	[1]	9,810,802	8,628,933
Common Stock Class A
Stockholders' equity
Common stock, par value (in dollars per share)		$ 0.01	$ 0.01
Common stock, shares authorized		62,500,000	62,500,000
Common stock, shares issued		36,542,091	35,030,097
Common stock, shares outstanding		26,731,289	26,401,163
Common stock, restricted shares		162,176	124,392
Treasury Stock, Shares		9,810,802	8,628,933
Common Stock Class B
Stockholders' equity
Common stock, par value (in dollars per share)		$ 0.01	$ 0.01
Common stock, shares authorized		62,500,000	62,500,000
Common stock, shares issued		0	0
Common stock, shares outstanding		0	0

[1] Share and per share amounts have been retroactively updated to reflect the one-for-four reverse stock split effective as of December 5, 2016.