Investments

9 Months Ended

Sep. 30, 2019

Available-for-sale Investments

Investments in available-for-sale securities at fair value were as follows for the periods ended (in thousands):



	September 30, 2019									December 31, 2018
Description of the Securities	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Fair Value		Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Fair Value
Agency securities	$	1,681	$	—	$	(2	)	$	1,679	$	314,982	$	333	$	(2,367	)	$	312,948
Corporate securities	61,044		1		(160		)	60,885		612,698		116		(4,156		)	608,658
Municipal securities	—		—		—			—		2,500		4		—			2,504
Government securities	14,179		7		(4		)	14,182		234,668		91		(935		)	233,824
Total	$	76,904	$	8	$	(166	)	$	76,746	$	1,164,848	$	544	$	(7,458	)	$	1,157,934

The change in net unrealized gains (losses) on available-for-sale securities recorded in Other comprehensive income includes unrealized gains (losses) that arose from changes in market value of specifically identified securities that were held during the period, gains (losses) that were previously unrealized, but have been recognized in current period net income due to sales and other than temporary impairments, as well as prepayments of available-for-sale investments purchased at a premium. See Note 13 for more information related to comprehensive income.

The average remaining maturities of the Company’s short-term and long-term available-for-sale investments at September 30, 2019 were approximately five months and two years, respectively.

Realized Gains and Losses on Available-for-sale Investments

For the three months ended September 30, 2019, the Company had no proceeds from the sales of available-for-sale investments. For the nine months ended September 30, 2019, the Company received proceeds from the sales of available-for-sale investments of $938.0 million. For the three and nine months ended September 30, 2018, the Company received proceeds from the sales of available-for-sale investments of $7.5 million and $442.4 million, respectively.

For the three months ended September 30, 2019, the Company had no realized gains on the sales of available-for-sale investments. For the nine months ended September 30, 2019, the Company had realized gains on the sales of available-for-sale investments of $1.5 million. For the three months ended September 30, 2018, the Company had no realized gains on the sales of available-for-sale investments. For the nine months ended September 30, 2018, the Company had $0.1 million in realized gains on the sales of available-for-sale investments.

For the three months ended September 30, 2019, the Company had no realized losses on available-for-sale investments. For the nine months ended September 30, 2019, the Company had realized losses on available-for-sale investments of $0.9 million. For the three and nine months ended September 30, 2018, the Company had realized losses on available-for-sale investments of $0.1 million and $1.5 million, respectively, primarily related to sales of these investments during these periods.

All realized gains and losses related to the sales of available-for-sale investments are included in Other income (expense), net, in the accompanying condensed consolidated statements of income.

Unrealized Losses on Available-for-Sale Investments

The gross unrealized losses on the Company’s available-for-sale investments that are not deemed to be other-than-temporarily impaired as of September 30, 2019 and December 31, 2018 were $0.2 million and $2.9 million, respectively. Because the Company does not currently intend to sell any of its investments in an unrealized loss position and it is more likely than not that it will not be required to sell the securities before the recovery of its amortized cost basis, which may not occur until maturity, it does not consider the securities to be other-than-temporarily impaired.

Equity Securities without Readily Determinable Fair Values

The Company held direct investments in privately-held companies of $12.3 million and $13.4 million as of September 30, 2019 and December 31, 2018, respectively, which are accounted for at cost, less impairment plus or minus adjustments resulting from observable price changes in orderly transactions for an identical or a similar investment of the same issuer. These investments are included in Other assets in the accompanying condensed consolidated balance sheets. The Company periodically reviews these investments for impairment and observable price changes on a quarterly basis, and adjusts the carrying value accordingly. The Company determined that there were no material adjustments resulting from observable price changes to the Company's investments in privately-held companies without a readily determinable fair value for the three and nine months ended September 30, 2019. The fair value of these investments represents a Level 3 valuation as the assumptions used in valuing these investments are not directly or indirectly observable. See Note 7 for detailed information on fair value measurements.

Equity Securities Accounted for at Net Asset Value

The Company held equity interests in certain private equity funds of $11.9 million and $10.9 million as of September 30, 2019 and December 31, 2018, respectively, which are accounted for under the net asset value practical expedient. These investments are included in Other assets in the accompanying condensed consolidated balance sheets. The net asset value of these investments is determined using quarterly capital statements from the funds, which are based on the Company’s contributions to the funds, allocation of profit and loss and changes in fair value of the underlying fund investments. These private equity funds focus on making venture capital investments, principally by investing in equity securities of early and late stage privately held corporations. The funds’ general partner shall determine the amount, timing and form (whether cash or in kind) of all distributions made by the funds. The Company may only transfer its investments in private equity fund interests subject to the general partner’s written consent and cannot trade its fund interests in established securities markets, secondary markets or equivalents thereof. The Company has unfunded commitments of $0.7 million as of September 30, 2019.