Investments (Tables)

12 Months Ended

Dec. 31, 2019

Investments, Debt and Equity Securities [Abstract]

Summary of Investments

Investments consist of:

	December 31,
	2019		2018
	(in thousands)
U.S. Treasury Bills	$	—	$	392,424
Equity securities:
Long-term incentive compensation-related	36,665		38,883
Seed capital	70,464		105,951
Other	73,202		73,409
Exchange-traded options	6,931		2,568
Investments in limited partnership hedge funds:
Long-term incentive compensation-related	14,237		13,546
Seed capital	33,124		67,153
Time deposits	18,281		8,783
Other	13,890		11,627
Total investments	$	266,794	$	714,344

Summary of the Cost and Fair Value of Available-For-Sale and Trading Investments

The portion of unrealized gains (losses) related to equity securities, as defined by ASC 321-10, held as of December 31, 2019 and 2018 were as follows:

	December 31,
	2019		2018
	(in thousands)
Net gain (losses) recognized during the period	$	31,890	$	(21,797	)
Less: net gains recognized during the period on equity securities sold during the period	18,138		1,515
Unrealized gains (losses) recognized during the period on equity securities held	$	13,752	$	(23,312	)