Consolidated Statements of Financial Condition (Parenthetical) (USD $) In Thousands, except Share data, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Allowance for doubtful accounts receivables	$ 28,777	$ 23,017
Property, accumulated amortization and depreciation	253,930	225,861
Intangible assets, accumulated amortization	$ 45,379	$ 35,281
Preferred stock, par value	$ 0.01	$ 0.01
Preferred stock, shares authorized	15,000,000	15,000,000
Series A Preferred Stock [Member]
Preferred stock, shares issued	7,921	7,921
Preferred stock, shares outstanding	7,921	7,921
Series B Preferred Stock [Member]
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Class A Common Stock [Member]
Common stock, par value	$ 0.01	$ 0.01
Common stock, shares authorized	500,000,000	500,000,000
Common stock, shares issued	129,056,081	128,216,423
Common stock held by subsidiaries, shares	8,317,065	12,802,938
Class B Common Stock [Member]
Common stock, par value	$ 0.01	$ 0.01
Common stock, shares authorized	1	1
Common stock, shares issued	1	1
Common stock, shares outstanding	1	1