Consolidated Statements of Cash Flows (USD $) In Thousands, unless otherwise specified	9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013
Cash flows from operating activities:
Net income	$ 51,429	$ 35,061
Non-cash items included in net income:
Income tax	5,396
Depreciation and amortization	600	249
Stock-based compensation	6,122	5,186
Deferred rent	1,620	111
Accretion to interest income and other	(76)	108
Changes in operating assets and liabilities:
Accounts receivable	2,049	(3,683)
Other assets	(811)	(720)
Fund management and administration payable	(1,579)	3,697
Compensation and benefits payable	(7,510)	7,235
Accounts payable and other liabilities	(590)	471
Net cash provided by operating activities	56,650	47,715
Cash flows from investing activities:
Purchase of fixed assets	(4,580)	(1,118)
Purchase of investments	(1,384)	(3,358)
Cash acquired on acquisition	1,349
Proceeds from the redemption of investments	868	2,693
Net cash used in investing activities	(3,747)	(1,783)
Cash flows from financing activities:
Shares repurchased	(6,259)	(1,413)
Proceeds from exercise of stock options	341	1,349
Net cash used in financing activities	(5,918)	(64)
Decrease in cash flows due to changes in foreign exchange rate	(14)
Net increase in cash and cash equivalents	46,971	45,868
Cash and cash equivalents-beginning of period	104,316	41,246
Cash and cash equivalents-end of period	151,287	87,114
Supplemental disclosure of cash flow information:
Cash paid for taxes	$ 66	$ 33