STATEMENTS OF OPERATIONS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Operating revenue
Management fee revenue, net	$ 1,567,431	$ 1,475,511	$ 1,376,190
Service agreement revenue	29,200	29,997	30,929
Total operating revenue	1,596,631	1,505,508	1,407,119
Operating expenses
Commissions	893,800	847,880	783,017
Salaries and employee benefits	213,356	226,713	206,690
All other operating expenses	197,111	198,374	194,565
Total operating expenses	1,304,267	1,272,967	1,184,272
Net revenue from operations	292,364	232,541	222,847
Investment income
Net investment income	20,547	17,791	16,536
Net realized investment gains	672	492	1,057
Net impairment losses recognized in earnings	(416)	(1,558)	(105)
Equity in earnings of limited partnerships	7,025	16,983	10,929
Total investment income	27,828	33,708	28,417
Interest expense, net	101
Income before income taxes	320,091	266,249	251,264
Income tax expense	109,725	91,571	83,759
Net income	$ 210,366	$ 174,678	$ 167,505
Class A
Net income per share
Common stock - basic (in dollars per share)	$ 4.52	$ 3.75	$ 3.59
Common stock - diluted (in dollars per share)	$ 4.01	$ 3.33	$ 3.18
Weighted average shares outstanding – Basic
Common stock - basic (in shares)	46,188,952	46,186,671	46,247,876
Weighted average shares outstanding – Diluted
Common stock - diluted (in shares)	52,435,303	52,498,811	52,616,234
Class B
Net income per share
Common stock - basic (in dollars per share)	$ 678	$ 563	$ 539
Common stock - diluted (in dollars per share)	$ 677	$ 562	$ 538
Weighted average shares outstanding – Basic
Common stock - basic (in shares)	2,542	2,542	2,542
Weighted average shares outstanding – Diluted
Common stock - diluted (in shares)	2,542	2,542	2,542