Cash Equivalents and Investments

Investments in Available-for-Sale and Trading Securities

The following table summarizes the Company's unrealized gains and losses and fair value of investments designated as available-for-sale and trading securities as of June 30, 2017 and December 31, 2016 (in millions):



	As of June 30, 2017									As of December 31, 2016
	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Estimated Fair Value		Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Estimated Fair Value
Fixed income securities:
Asset-backed securities	$	309.6	$	—	$	(0.3	)	$	309.3	$	303.0	$	0.2	$	(0.2	)	$	303.0
Certificates of deposit	45.7		—		—			45.7		66.1		—		—			66.1
Commercial paper	167.8		—		—			167.8		147.7		—		—			147.7
Corporate debt securities	863.1		1.0		(1.0		)	863.1		846.5		0.4		(2.0		)	844.9
Foreign government debt securities	44.0		—		(0.1		)	43.9		34.0		—		(0.1		)	33.9
Time deposits	290.7		—		—			290.7		264.6		—		—			264.6
U.S. government agency securities	163.5		—		(0.5		)	163.0		127.0		—		(0.3		)	126.7
U.S. government securities	359.1		0.1		(0.5		)	358.7		390.7		0.1		(0.4		)	390.4
Total fixed income securities	2,243.5		1.1		(2.4		)	2,242.2		2,179.6		0.7		(3.0		)	2,177.3
Money market funds	1,206.6		—		—			1,206.6		592.2		—		—			592.2
Mutual funds	8.3		—		—			8.3		8.0		—		—			8.0
Publicly-traded equity securities	6.2		—		(0.9		)	5.3		5.3		—		(0.7		)	4.6
Total available-for-sale securities	3,464.6		1.1		(3.3		)	3,462.4		2,785.1		0.7		(3.7		)	2,782.1
Trading securities in mutual funds	23.9		—		—			23.9		21.0		—		—			21.0
Total	$	3,488.5	$	1.1	$	(3.3	)	$	3,486.3	$	2,806.1	$	0.7	$	(3.7	)	$	2,803.1

Reported as:
Cash equivalents	$	1,589.2	$	—	$	—		$	1,589.2	$	907.1	$	—	$	—		$	907.1
Restricted investments	75.0		—		—			75.0		71.9		—		—			71.9
Short-term investments	754.0		0.1		(1.4		)	752.7		753.4		0.1		(1.2		)	752.3
Long-term investments	1,070.3		1.0		(1.9		)	1,069.4		1,073.7		0.6		(2.5		)	1,071.8
Total	$	3,488.5	$	1.1	$	(3.3	)	$	3,486.3	$	2,806.1	$	0.7	$	(3.7	)	$	2,803.1

The following table presents the contractual maturities of the Company's total fixed income securities as of June 30, 2017 (in millions):



	Amortized Cost		Estimated Fair Value
Due in less than one year	$	1,173.2	$	1,172.8
Due between one and five years	1,070.3		1,069.4
Total	$	2,243.5	$	2,242.2

The following tables present the Company's available-for-sale securities that were in an unrealized loss position as of June 30, 2017 and December 31, 2016 (in millions):



	As of June 30, 2017
	Less than 12 Months					12 Months or Greater				Total
	Fair Value		Unrealized Loss			Fair Value		Unrealized Loss		Fair Value		Unrealized Loss
Fixed income securities:
Asset-backed securities	$	270.1	$	(0.3	)	$	—	$	—	$	270.1	$	(0.3	)
Corporate debt securities	391.3		(1.0		)	—		—		391.3		(1.0		)
Foreign government debt securities	34.2		(0.1		)	—		—		34.2		(0.1		)
U.S. government agency securities	132.5		(0.5		)	—		—		132.5		(0.5		)
U.S. government securities	249.7		(0.5		)	—		—		249.7		(0.5		)
Total fixed income securities	1,077.8		(2.4		)	—		—		1,077.8		(2.4		)
Publicly-traded equity securities	5.3		(0.9		)	—		—		5.3		(0.9		)
Total available-for-sale securities	$	1,083.1	$	(3.3	)	$	—	$	—	$	1,083.1	$	(3.3	)



	As of December 31, 2016
	Less than 12 Months					12 Months or Greater					Total
	Fair Value		Unrealized Loss			Fair Value		Unrealized Loss			Fair Value		Unrealized Loss
Fixed income securities:
Asset-backed securities	$	122.2	$	(0.2	)	$	—	$	—		$	122.2	$	(0.2	)
Corporate debt securities	470.8		(1.9		)	76.7		(0.1		)	547.5		(2.0		)
Foreign government debt securities	20.3		(0.1		)	—		—			20.3		(0.1		)
U.S. government agency securities	106.7		(0.3		)	—		—			106.7		(0.3		)
U.S. government securities	254.1		(0.4		)	—		—			254.1		(0.4		)
Total fixed income securities	974.1		(2.9		)	76.7		(0.1		)	1,050.8		(3.0		)
Publicly-traded equity securities	4.6		(0.7		)	—		—			4.6		(0.7		)
Total available-for-sale securities	$	978.7	$	(3.6	)	$	76.7	$	(0.1	)	$	1,055.4	$	(3.7	)

The Company had 517 and 494 investments in unrealized loss positions as of June 30, 2017 and December 31, 2016, respectively. The gross unrealized losses related to these investments were primarily due to changes in market interest rates and stock prices.

For available-for-sale debt securities that have unrealized losses, the Company evaluates whether (i) it has the intention to sell any of these investments and (ii) whether it is more likely than not that it will be required to sell any of these investments before recovery of the entire amortized cost basis. As of June 30, 2017, the Company anticipates that it will recover the entire amortized cost basis of such available-for-sale debt securities and has determined that no other-than-temporary impairments associated with credit losses were required to be recognized during the three and six months ended June 30, 2017. During the three and six months ended June 30, 2016, there were no other-than-temporary impairments associated with these investments.

For available-for-sale equity securities that have unrealized losses, the Company evaluates whether there is an indication of other-than-temporary impairments. This determination is based on several factors, including the financial condition and near-term prospects of the issuer and the Company's intent and ability to hold the publicly-traded equity securities for a period of time sufficient to allow for any anticipated recovery in market value. During the three and six months ended June 30, 2017 and June 30, 2016, there were no other-than-temporary impairments associated with these investments.

During the three and six months ended June 30, 2017 and June 30, 2016, there were no material gross realized gains or losses from either available-for-sale securities or from trading securities.

Restricted Cash and Investments

There have been no material changes to the composition of the Company's restricted cash and investments as described in Note 4, Cash Equivalents and Investments, in Notes to Consolidated Financial Statements in Item 8 of Part II of the Form 10-K. The restricted investments are designated as available-for-sale securities except relating to the non-qualified deferred compensation plan which are designated as trading securities. As of June 30, 2017, total restricted cash and investments was $115.5 million, of which $52.1 million was included in prepaid expenses and other current assets and $63.4 million was included in restricted cash and investments, respectively, on the Condensed Consolidated Balance Sheets.

Investments in Privately-Held Companies

As of June 30, 2017 and December 31, 2016, the carrying values of the Company's investments in privately-held companies of $72.5 million and $62.7 million, respectively, were included in other long-term assets in the Condensed Consolidated Balance Sheets. These investments include debt and redeemable preferred stock securities that are carried at fair value, and non-redeemable preferred stock securities that are carried at cost. As of June 30, 2017 and December 31, 2016, the carrying value of the investments accounted for under the cost method were $30.2 million and $19.0 million, respectively. See Note 4, Fair Value Measurements, for the Company's investments in privately-held companies that are carried at fair value.

The Company adjusts the carrying value for its investments in privately-held companies that are carried at cost for any impairment if the fair value is less than the carrying value of the respective assets on an other-than-temporary basis. There were no impairment charges for the three and six months ended June 30, 2017 and for the three months ended June 30, 2016. During the six months ended June 30, 2016, the Company determined that certain investments in privately-held companies were other than-temporarily impaired, resulting in impairment charges of $5.1 million, that was recorded within other expense, net in the Condensed Consolidated Statement of Operations.