Goodwill (Changes To The Carrying Amount) (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Goodwill [Roll Forward]
Beginning balance	$ 115,238	$ 90,501
Benefit applied to reduce goodwill	(78)	(68)	$ (77)
Adjustments related to allocation of KMS and Highland purchase price	1,116
Benefit applied to reduce goodwill	9,296	24,805
Ending balance	125,572	115,238	90,501
Ladenburg
Goodwill [Roll Forward]
Beginning balance	301	301
Benefit applied to reduce goodwill	0	0
Adjustments related to allocation of KMS and Highland purchase price	0
Benefit applied to reduce goodwill	0	0
Ending balance	301	301	301
Independent brokerage and advisory services
Goodwill [Roll Forward]
Beginning balance	103,422	90,200
Benefit applied to reduce goodwill	(78)	(68)
Adjustments related to allocation of KMS and Highland purchase price	(68)
Benefit applied to reduce goodwill	9,296	13,290
Ending balance	112,572	103,422	90,200
Insurance Brokerage
Goodwill [Roll Forward]
Beginning balance	11,515	0
Benefit applied to reduce goodwill	0	0
Adjustments related to allocation of KMS and Highland purchase price	$ 1,184
Benefit applied to reduce goodwill		11,515
Ending balance	$ 12,699	$ 11,515	$ 0