Segment Information (Segment Information 1) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Segment Reporting Information [Line Items]
Commissions	$ 558,683	$ 445,734	$ 394,414
Series A Preferred Stock
Segment Reporting Information [Line Items]
Commissions	5,148
Series A Preferred Stock \| Ladenburg
Segment Reporting Information [Line Items]
Commissions	4,240
Series A Preferred Stock \| Independent brokerage and advisory services
Segment Reporting Information [Line Items]
Commissions	908
Employee brokerage commission expenses \| Series A Preferred Stock
Segment Reporting Information [Line Items]
Commissions	2,603
Employee brokerage commission expenses \| Series A Preferred Stock \| Ladenburg
Segment Reporting Information [Line Items]
Commissions	$ 2,545