Investments (Tables)

3 Months Ended

Mar. 31, 2018

Investments [Abstract]

Summary of investments

The following table summarizes our investments as of March 31, 2018 and December 31, 2017 (in thousands):

	As of March 31, 2018
	Cost		Cumulative Unrealized Gains		Total
Investments in publicly traded companies	$	67,801	$	95,870	$	163,671
Investments in privately held entities without readily determinable fair values (previously cost method investments):
Investments in privately held entities that report NAV	159,231		106,235		265,466
Investments in privately held entities that do not report NAV (see discussion below)
Entities with observable price changes since January 1, 2018	23,491		11,043		34,534
Entities without observable price changes since January 1, 2018	260,639		—		260,639
Total investments	$	511,162	$	213,148	$	724,310

Cumulative unrealized gains on investments in privately held entities that do not report NAV aggregating $11.0 million as of March 31, 2018, consisted of upward adjustments representing unrealized gains of $11.4 million and downward adjustments representing unrealized losses of $353 thousand recognized in net income during the three months ended March 31, 2018. We adjusted our investments in privately held entities that do not report NAV based on observable price changes from subsequent equity offerings. The subsequent equity offerings observed were for similar securities to those we hold as the securities had similar (i) voting rights, (ii) distribution preferences, and (iii) conversion rights.

	As of December 31, 2017
	Cost		Cumulative Unrealized Gains		Total
Investments in publicly traded companies	$	59,740	$	49,771	$	109,511
Investments in privately held entities without readily determinable fair values (cost method investments):
Investments in privately held entities that report NAV	148,627		N/A		148,627
Investments in privately held entities that do not report NAV	265,116		N/A		265,116
Total investments	$	473,483	$	49,771	$	523,254

Schedule of net investment income

Our investment income for the three months ended March 31, 2018 consisted of the following (in thousands):

	Three months ended March 31, 2018
Realized gains and losses	$	13,332
Unrealized gains and losses:
Investments in publicly traded companies	46,099
Investments in privately held entities without readily determinable fair values:
Investments in privately held entities that report NAV	15,087
Investments in privately held entities that do not report NAV (upward adjustments for observable price changes)	11,043
Unrealized gains and losses	$	72,229
Investment income	$	85,561