Goodwill (Changes To The Carrying Amount) (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Goodwill [Roll Forward]
Beginning balance	$ 125,572	$ 115,238
Benefit applied to reduce goodwill		(78)	$ (68)
Adjustments related to allocation of KMS and Highland purchase price	(2,870)	1,116
Business acquisitions	1,329	9,296
Ending balance	124,031	125,572	115,238
Ladenburg
Goodwill [Roll Forward]
Beginning balance	301	301
Benefit applied to reduce goodwill		0
Adjustments related to allocation of KMS and Highland purchase price	0	0
Business acquisitions	0	0
Ending balance	301	301	301
Independent brokerage and advisory services
Goodwill [Roll Forward]
Beginning balance	112,572	103,422
Benefit applied to reduce goodwill		(78)
Adjustments related to allocation of KMS and Highland purchase price	2,870	(68)
Business acquisitions	1,329	9,296
Ending balance	111,031	112,572	103,422
Insurance Brokerage
Goodwill [Roll Forward]
Beginning balance	12,699	11,515
Benefit applied to reduce goodwill		0
Adjustments related to allocation of KMS and Highland purchase price	0	1,184
Business acquisitions	0	0
Ending balance	$ 12,699	$ 12,699	$ 11,515