STATEMENTS OF OPERATIONS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Operating revenue
Management fee revenue, net	$ 1,475,511	$ 1,376,190	$ 1,266,401
Service agreement revenue	29,997	30,929	30,930
Total operating revenue	1,505,508	1,407,119	1,297,331
Operating expenses
Commissions	847,880	783,017	710,058
Salaries and employee benefits	226,713	206,690	207,559
All other operating expenses	198,374	194,565	170,378
Total operating expenses	1,272,967	1,184,272	1,087,995
Net revenue from operations	232,541	222,847	209,336
Investment income
Net investment income	17,791	16,536	15,027
Net realized investment gains	492	1,057	945
Net impairment losses recognized in earnings	(1,558)	(105)	(388)
Equity in earnings of limited partnerships	16,983	10,929	21,694
Total investment income	33,708	28,417	37,278
Income before income taxes	266,249	251,264	246,614
Income tax expense	91,571	83,759	84,003
Net income	$ 174,678	$ 167,505	$ 162,611
Class A
Net income per share
Common stock - basic (in dollars per share)	$ 3.75	$ 3.59	$ 3.46
Common stock - diluted (in dollars per share)	$ 3.33	$ 3.18	$ 3.08
Weighted average shares outstanding – Basic
Common stock - basic (in shares)	46,186,671	46,247,876	46,660,651
Weighted average shares outstanding – Diluted
Common stock - diluted (in shares)	52,498,811	52,616,234	52,855,757
Class B
Net income per share
Common stock - basic (in dollars per share)	$ 563	$ 539	$ 520
Common stock - diluted (in dollars per share)	$ 562	$ 538	$ 519
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