Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Cash Flows from Operating Activities:
Net income (loss)	$ 22,468	$ 23,827
Adjustments to reconcile net income to net cash provided by (used in) operating activities:
Depreciation expense, intangible asset and other amortization	9,874	6,819
Stock-based compensation	5,629	5,909
Amortization of deferred commissions	980	737
Payments of deferred commissions	(455)	(1,075)
Equity in earnings of equity method investments	(496)	(1,322)
Sales (purchases) of investments, net	9,413	4,718
Deferred taxes, net	(1,705)	646
Changes in operating assets and liabilities:
Accounts receivable, net and other assets	(2,732)	2,629
Accrued compensation and benefits, accounts payable, accrued liabilities and other liabilities	(60,857)	(51,148)
Operating activities of consolidated investment products (CIP):
Net cash provided by (used in) operating activities	(23,215)	(61,755)
Cash Flows from Investing Activities:
Capital expenditures	(2,568)	(1,275)
Sale of available-for-sale securities	2,044	0
Purchases of available-for-sale securities	0	(20,302)
Net cash provided by (used in) investing activities	(2,095)	(21,577)
Cash Flows from Financing Activities:
Repayments on debt	(12,413)	(650)
Payment of deferred financing costs	0	(3,400)
Common stock dividends paid	(4,441)	(3,412)
Preferred stock dividends paid	(2,084)	(2,084)
Repurchases of common shares	(14,999)	0
Stock options exercised	449	698
Taxes paid related to net share settlement of restricted stock units	(4,804)	(5,014)
Net subscriptions received from (redemptions/distributions paid to) noncontrolling interests	6,012
Net subscriptions received from (redemptions/distributions paid to) noncontrolling interests		(589)
Net cash provided by (used in) financing activities	(31,280)	(14,451)
Net increase (decrease) in cash, cash equivalents and restricted cash	(56,590)	(97,783)
Cash, cash equivalents and restricted cash, beginning of period	254,656	234,282
Cash, Cash Equivalent and Restricted Cash, End of Period	198,066	136,499
Non-Cash Investing Activities:
Change in accrual for capital expenditures	(1,267)	(375)
Non-Cash Financing Activities:
Increase (decrease) to noncontrolling interest due to consolidation (deconsolidation) of CIP, net	(6,423)	0
Common stock dividends payable	3,865	3,248
Preferred stock dividends payable	2,084	2,084
Reconciliation of cash, cash equivalents and restricted cash
Cash, cash equivalents and restricted cash at end of period	254,656	234,282
Consolidated entity excluding consolidated investment products
Adjustments to reconcile net income to net cash provided by (used in) operating activities:
Realized and unrealized (gains) losses on investments, net	(3,292)	(333)
Consolidated investment products
Adjustments to reconcile net income to net cash provided by (used in) operating activities:
Realized and unrealized (gains) losses on investments, net	1,497	(2,382)
Operating activities of consolidated investment products (CIP):
Purchases of investments by CIP	(157,158)	(264,398)
Sales of investments by CIP	152,572	217,564
Net purchases of short term investments by CIP	(911)	(177)
Sales (purchases) of securities sold short by CIP, net	1,064	190
Change in other assets of CIP	578	(492)
Change in liabilities of CIP	316	(3,467)
Cash Flows from Investing Activities:
Change in cash and cash equivalents of CIP due to consolidation (deconsolidation), net	(1,571)	0
Cash Flows from Financing Activities:
Borrowings (payments) on borrowings by CIP	0	350,000
Proceeds from issuance of notes payable by CIP	1,000	0
Repayment of notes payable by CIP	$ 0	$ (350,000)