Investments (Tables)

12 Months Ended

Dec. 31, 2019

Investments [Abstract]

Summary of investments

The following tables summarize our investments as of December 31, 2019, and 2018 (in thousands):

	December 31, 2019
	Cost		Adjustments		Carrying Amount
Investments:
Publicly traded companies	$	148,109	$	170,528	$	318,637
Entities that report NAV	271,276		162,626		433,902
Entities that do not report NAV:
Entities with observable price changes	42,045		68,489		110,534
Entities without observable price changes	277,521		—		277,521
Total investments	$	738,951	$	401,643	$	1,140,594

	December 31, 2018
	Cost		Adjustments		Carrying Amount
Investments:
Publicly traded companies	$	121,121	$	62,884	$	184,005
Entities that report NAV	204,646		113,159		317,805
Entities that do not report NAV:
Entities with observable price changes	39,421		64,112		103,533
Entities without observable price changes	286,921		—		286,921
Total investments	$	652,109	$	240,155	$	892,264

Schedule of net investment income

Our investment income for the years ended December 31, 2019 and 2018, consisted of the following (in thousands):

	Year Ended December 31, 2019
	Unrealized Gains (Losses)			Realized Gains (Losses)			Total
Investments held at December 31, 2019:
Publicly traded companies	$	130,802		$	—		$	130,802
Entities that report NAV	49,440			—			49,440
Entities that do not report NAV, held at period end	4,378			(17,124		)	(12,746		)
Total investments held at December 31, 2019	184,620			(17,124		)	167,496
Investment dispositions during the year ended December 31, 2019:
Recognized in the current period	—			27,151			27,151
Previously recognized gains	(23,131		)	23,131			—
Total investment dispositions during the year ended December 31, 2019	(23,131		)	50,282			27,151
Investment income	$	161,489		$	33,158		$	194,647

	Year Ended December 31, 2018
	Unrealized Gains			Realized (Losses) Gains			Total
Investments held at December 31, 2018:
Publicly traded companies	$	27,944		$	—		$	27,944
Entities that report NAV	22,389			—			22,389
Entities that do not report NAV, held at period end	64,112			(5,483		)	58,629
Total investments held at December 31, 2018	114,445			(5,483		)	108,962
Investment dispositions during the year ended December 31, 2018:
Recognized in the current period	—			27,801			27,801
Previously recognized gains	(14,811		)	14,811			—
Total investment dispositions during the year ended December 31, 2018	(14,811		)	42,612			27,801
Investment income	$	99,634		$	37,129		$	136,763