Fair Value Measurements (Tables)

3 Months Ended

Mar. 31, 2019

Assets And Liabilities Measured At Fair Value On A Recurring Basis

Assets and Liabilities Measured at Fair Value on a Recurring Basis



	As of March 31, 2019		Quoted Prices In Active Markets for Identical Assets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)
	(In thousands)
Assets:
Cash and cash equivalents:
Cash	$	691,539	$	691,539	$	—	$	—
Money market funds	916,800		916,800		—		—
Corporate securities	4,340		—		4,340		—
Available-for-sale securities:
Agency securities	69,947		—		69,947		—
Corporate securities	118,298		—		117,298		1,000
Government securities	71,696		—		71,696		—
Prepaid expenses and other current assets:
Foreign currency derivatives	1,782		—		1,782		—
Total assets	$	1,874,402	$	1,608,339	$	265,063	$	1,000
Accrued expenses and other current liabilities:
Foreign currency derivatives	1,188		—		1,188		—
Total liabilities	$	1,188	$	—	$	1,188	$	—



	As of December 31, 2018		Quoted Prices In Active Markets for Identical Assets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)
	(In thousands)
Assets:
Cash and cash equivalents:
Cash	$	505,363	$	505,363	$	—	$	—
Money market funds	88,126		88,126		—		—
Agency securities	3,296		—		3,296		—
Corporate securities	9,371		—		9,371		—
Government securities	12,610		—		12,610		—
Available-for-sale securities:
Agency securities	312,948		—		312,948		—
Corporate securities	608,658		—		607,945		713
Municipal securities	2,504		—		2,504		—
Government securities	233,824		—		233,824		—
Prepaid expenses and other current assets:
Foreign currency derivatives	764		—		764		—
Total assets	$	1,777,464	$	593,489	$	1,183,262	$	713
Accrued expenses and other current liabilities:
Foreign currency derivatives	2,543		—		2,543		—
Total liabilities	$	2,543	$	—	$	2,543	$	—

Fair Value, by Balance Sheet Grouping

As of March 31, 2019, the fair value of the $750.0 million of unsecured senior notes due December 1, 2027 (the “2027 Notes") and the Convertible Notes, which was determined based on inputs that are observable in the market (Level 2) based on the closing trading price per $100 as of the last day of trading for the quarter ended March 31, 2019, and carrying value of debt instruments (carrying value excludes the equity component of the Company’s Convertible Notes classified in equity) was as follows (in thousands):



	Fair Value		Carrying Value
2027 Notes	$	741,825	$	742,100
Convertible Notes	$	1,651,210	$	1,163,199