CONDENSED CONSOLIDATED STATEMENTS OF INCOME (UNAUDITED) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
REVENUES
Commissions and fees	$ 1,656,951	$ 1,567,460	$ 1,355,503
Investment income	1,004	747	638
Other income, net	2,554	7,589	7,138
Total revenues	1,660,509	1,575,796	1,363,279
EXPENSES
Employee compensation and benefits	841,439	791,749	683,000
Non-cash stock-based compensation	15,513	19,363	22,603
Other operating expenses	251,055	235,328	195,677
Loss/(gain) on disposal	(619)	47,425	0
Amortization	87,421	82,941	67,932
Depreciation	20,890	20,895	17,485
Interest	39,248	28,408	16,440
Change in estimated acquisition earn-out payables	3,003	9,938	2,533
Total expenses	1,257,950	1,236,047	1,005,670
Income before income taxes	402,559	339,749	357,609
Income taxes	159,241	132,853	140,497
Net income	$ 243,318	$ 206,896	$ 217,112
Net income per share:
Basic (in dollars per share)	$ 1.72	$ 1.43	$ 1.50
Diluted (in dollars per share)	1.70	1.41	1.48
Dividends declared per share (in dollars per share)	$ 0.45	$ 0.41	$ 0.37