Consolidated Statements of Operations (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Revenues:
Revenues	$ 475,651	$ 400,646	$ 931,337	$ 815,408
Expenses:
Subadvisory, distribution and other asset management costs	55,827	44,182	105,991	89,519
Software royalties and other information processing costs	7,471	7,389	13,213	14,836
Compensation, benefits and other personnel	141,779	125,331	279,000	256,812
Stock-based compensation	10,103	7,062	19,855	13,991
Consulting, outsourcing and professional fees	55,449	57,111	109,789	110,401
Data processing and computer related	27,375	24,506	53,096	47,210
Facilities, supplies and other costs	18,479	13,973	35,727	30,769
Amortization	14,723	13,140	29,075	26,217
Depreciation	8,424	7,640	16,733	15,113
Total expenses	339,630	300,334	662,479	604,868
Income from operations	136,021	100,312	268,858	210,540
Net gain (loss) from investments	377	1,903	709	(2,086)
Interest and dividend income	878	1,370	1,823	4,573
Interest expense	(130)	(151)	(253)	(303)
Equity in earnings of unconsolidated affiliate	35,065	28,276	68,415	58,183
Income before income taxes	172,211	131,710	339,552	270,907
Income taxes	38,433	30,644	76,304	60,599
Net income	$ 133,778	$ 101,066	$ 263,248	$ 210,308
Basic earnings per common share (in USD per share)	$ 0.94	$ 0.69	$ 1.85	$ 1.42
Shares used to compute basic earnings per share (in shares)	142,074	147,478	142,638	148,473
Diluted earnings per common share (in USD per share)	$ 0.93	$ 0.68	$ 1.82	$ 1.39
Shares used to compute diluted earnings per share (in shares)	144,212	149,598	144,759	150,983
Dividends declared per common share (in USD per share)	$ 0.37	$ 0.35	$ 0.37	$ 0.35
Asset management, administration and distribution fees
Revenues:
Revenues	$ 382,509	$ 320,577	$ 750,155	$ 652,430
Information processing and software servicing fees
Revenues:
Revenues	$ 93,142	$ 80,069	$ 181,182	$ 162,978