Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016
Cash Flows from Operating Activities:
Net income	$ 13,773	$ 20,570
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation expense, intangible asset and other amortization	4,894	3,009
Stock-based compensation	9,490	6,658
Excess tax benefit from stock-based compensation	0	(164)
Amortization of deferred commissions	1,072	1,365
Payments of deferred commissions	(1,389)	(921)
Equity in earnings of equity method investments	(679)	(201)
Realized gain on sale of equity method investment	0	(2,883)
Sales of trading securities, net	5,558	11,122
Deferred taxes, net	(576)	7,190
Changes in operating assets and liabilities:
Accounts receivable, net and other assets	(7,359)	576
Accrued compensation and benefits, accounts payable, accrued liabilities and other liabilities	(22,465)	(25,430)
Operating activities of consolidated investment products (CIP):
Net cash provided by operating activities	54,632	51,945
Cash Flows from Investing Activities:
Capital expenditures	(678)	(1,093)
Proceeds from sale of equity method investment	0	8,621
Equity method investment contributions	0	(759)
Acquisition of business (cash paid $471.4 million, less cash acquired $77.6 million)	(393,784)	0
Purchases of available-for-sale securities	(130)	(121)
Net cash (used in) provided by investing activities	(389,126)	6,751
Cash Flows from Financing Activities:
Issuance of debt	260,000	0
Repayments on credit facility and other debt	(30,271)	0
Payment of deferred financing costs	(15,520)	0
Proceeds from issuance of mandatory convertible preferred stock, net of issuance costs	111,004	0
Proceeds from issuance of common stock, net of issuance costs	109,487	0
Common stock dividends paid	(6,060)	(7,638)
Preferred stock dividends paid	(2,084)	0
Repurchases of common shares	0	(61,809)
Proceeds from exercise of stock options	86	400
Taxes paid related to net share settlement of restricted stock units	(3,029)	(1,332)
Excess tax benefits from stock-based compensation	0	164
Contributions of noncontrolling interests, net	7,733	1,537
Net cash provided by financing activities	430,846	91,590
Net increase in cash and cash equivalents	96,352	150,286
Cash and cash equivalents, beginning of period	82,687	97,384
Cash and Cash Equivalents, End of Period	179,039	247,670
Non-Cash Investing Activities:
Change in accrual for capital expenditures	(174)	45
Non-Cash Financing Activities:
Decrease to noncontrolling interest due to deconsolidation of consolidated investment products	11,286	(52,874)
Stock issued for acquisition of business	21,738	0
Contingent consideration for acquisition of business	51,690	0
Common stock dividends payable	3,248	3,473
Preferred stock dividends payable	2,084	0
Accrued stock issuance costs	334	0
Consolidated entity excluding consolidated investment products
Adjustments to reconcile net income to net cash provided by operating activities:
Realized and unrealized (gains) losses on trading securities, net	(1,584)	260
Cash Flows from Financing Activities:
Cash and cash equivalents, beginning of period	64,588
Cash and Cash Equivalents, End of Period	127,571
Consolidated investment products
Adjustments to reconcile net income to net cash provided by operating activities:
Realized and unrealized (gains) losses on trading securities, net	(2,879)	(6,364)
Operating activities of consolidated investment products (CIP):
Purchases of investments by CIP	(150,500)	(334,459)
Sales of investments by CIP	205,347	356,437
Net purchases of short term investments by CIP	265	6,515
Sales (purchases) of securities sold short by CIP, net	153	(4,455)
Change in cash pledged or on deposit of CIP	130	9,582
Change in other assets of CIP	1,589	(585)
Change in liabilities of CIP	(208)	404
Amortization of discount on notes payable of CIP	0	3,719
Cash Flows from Investing Activities:
Change in cash and cash equivalents of consolidated investment products due to consolidation, net	5,466	103
Cash Flows from Financing Activities:
Repayment of debt of CIP	0	(156,012)
Proceeds from issuance of notes payable by CIP	0	316,280
Repayment of notes payable by CIP	(500)	$ 0
Cash and cash equivalents, beginning of period	18,099
Cash and Cash Equivalents, End of Period	$ 51,468