Cash and Investments (Tables)

3 Months Ended

Mar. 31, 2017

Investments, Debt and Equity Securities [Abstract]

Schedule of Available-for-Sale Securities

The following tables summarize cash and cash equivalents, investments, and restricted cash and investments by balance sheet line item as of March 31, 2017 and December 31, 2016 (in thousands):



	March 31, 2017
	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Fair Value
Cash and cash equivalents	$	183,179	$	—	$	—		$	183,179
Short-term investments	241,247		22		(175		)	241,094
Long-term investments	47,416		15		(80		)	47,351
Long-term restricted cash and investments	4,150		—		—			4,150
Total cash and investments	$	475,992	$	37	$	(255	)	$	475,774



	December 31, 2016
	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Fair Value
Cash and cash equivalents	$	151,686	$	—	$	—		$	151,686
Short-term investments	268,234		13		(130		)	268,117
Long-term investments	55,792		1		(192		)	55,601
Long-term restricted cash and investments	4,150		—		—			4,150
Total cash and investments	$	479,862	$	14	$	(322	)	$	479,554

Summary of Cash Equivalents and Investments by Security Type

The amounts presented exclude cash, but include investments classified as cash equivalents (in thousands):



	March 31, 2017
	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Fair Value
Money market funds	$	44,641	$	—	$	—		$	44,641
Commercial paper	193,968		—		—			193,968
Corporate bonds	175,244		37		(220		)	175,061
U.S. Treasury and government sponsored enterprises	43,321		—		(35		)	43,286
Total investments	$	457,174	$	37	$	(255	)	$	456,956



	December 31, 2016
	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Fair Value
Money market funds	$	71,457	$	—	$	—		$	71,457
Commercial paper	165,375		—		—			165,375
Corporate bonds	152,712		3		(308		)	152,407
U.S. Treasury and government sponsored enterprises	70,730		11		(14		)	70,727
Total investments	$	460,274	$	14	$	(322	)	$	459,966

Summary of Available-for-Sale Securities by Contractual Maturity

The following table summarizes the fair value of securities classified as available-for-sale by contractual maturity as of March 31, 2017 (in thousands):



	Mature within One Year		After One Year through Two Years		Fair Value
Money market funds	$	44,641	$	—	$	44,641
Commercial paper	193,968		—		193,968
Corporate bonds	132,355		42,706		175,061
U.S. Treasury and government sponsored enterprises	40,639		2,647		43,286
Total investments	$	411,603	$	45,353	$	456,956