Fair Value Measurements (Tables)

9 Months Ended

Sep. 30, 2017

Fair Value Disclosures [Abstract]

Financial assets subject to fair value measurements (excluding VIE cash and cash equivalents, which are recorded as Restricted cash and cash equivalents (VIE))

The following table sets forth the Company’s financial assets (excluding VIE cash and cash equivalents, which are recorded as Restricted cash and cash equivalents (VIE)) and liabilities subject to fair value measurements:

	Fair Value Measurements as of September 30, 2017
				Fair Value Hierarchy
	Total			Level 1		Level 2			Level 3
	(in thousands)
Financial instruments carried at fair value (asset position):
Cash equivalents:
Money market funds	$	466,702		$	466,702	$	—		$	—
Government-sponsored enterprise securities	14,979			14,979		—			—
Corporate debt securities	4,488			—		4,488			—
Commercial paper	14,608			—		14,608			—
Marketable securities:
Corporate equity securities	56,944			56,944		—			—
Corporate debt securities	295,171			—		295,171			—
Commercial paper	75,167			—		75,167			—
Prepaid and other current assets:
Foreign currency forward contracts	42			—		42			—
Other assets:
Foreign currency forward contracts	8			—		8			—
Total financial assets	$	928,109		$	538,625	$	389,484		$	—
Financial instruments carried at fair value (liability position):
Other liabilities, current portion:
Foreign currency forward contracts	$	(13,897	)	$	—	$	(13,897	)	$	—
Other liabilities, excluding current portion:
Foreign currency forward contracts	(977		)	—		(977		)	—
Total financial liabilities	$	(14,874	)	$	—	$	(14,874	)	$	—

	Fair Value Measurements as of December 31, 2016
				Fair Value Hierarchy
	Total			Level 1		Level 2			Level 3
	(in thousands)
Financial instruments carried at fair value (asset position):
Cash equivalents:
Money market funds	$	280,560		$	280,560	$	—		$	—
Marketable securities:
Government-sponsored enterprise securities	15,508			15,508		—			—
Corporate equity securities	64,560			64,560		—			—
Commercial paper	59,404			—		59,404			—
Corporate debt securities	111,140			—		111,140			—
Prepaid and other current assets:
Foreign currency forward contracts	14,407			—		14,407			—
Other assets:
Foreign currency forward contracts	1,186			$	—	1,186			$	—
Total financial assets	$	546,765		$	360,628	$	186,137		$	—
Financial instruments carried at fair value (liability position):
Other liabilities, current portion:
Foreign currency forward contracts	$	(144	)	$	—	$	(144	)	$	—
Total financial liabilities	$	(144	)	$	—	$	(144	)	$	—