Marketable Securities (Tables)

12 Months Ended

Dec. 31, 2018

Investments, Debt and Equity Securities [Abstract]

Schedule of Available-for-Sale Securities Reconciliation

The Company’s marketable securities within cash equivalents and investments included in the consolidated balance sheets are detailed as follows (in thousands):


	December 31, 2018
	Amortized		Unrealized		Unrealized			Fair
	Cost		Gain		Loss			Value
U.S. Treasury securities	$	164,619	$	16	$	(320	)	$	164,315
Foreign government securities		3,486		1		(24	)		3,463
Corporate debt securities		725,778		41		(2,760	)		723,059
Time deposits		108,638		—		—			108,638

Total	$	1,002,521	$	58	$	(3,104	)	$	999,475

Amounts included in:
Cash equivalents	$	60,532	$	—	$	(1	)	$	60,531
Investments		941,989		58		(3,103	)		938,944

Total	$	1,002,521	$	58	$	(3,104	)	$	999,475


	December 31, 2017
	Amortized Cost		Unrealized Gain		Unrealized Loss			Fair Value
U.S. Treasury securities	$	593,599	$	82	$	(1,693	)	$	591,988
Foreign government securities		6,982		—		(30	)		6,952
Corporate debt securities		1,977,329		897		(3,066	)		1,975,160
Time deposits		371,515		—		(4	)		371,511
Equity securities		77		70		—			147

Total	$	2,949,502	$	1,049	$	(4,793	)	$	2,945,758


Amounts included in:
Cash equivalents	$	194,377	$	—	$	(1	)	$	194,376
Investments		2,755,125		1,049		(4,792	)		2,751,382

Total	$	2,949,502	$	1,049	$	(4,793	)	$	2,945,758

Investments Classified By Contractual Maturity Date

The estimated fair value of marketable debt securities by maturity date is as follows (in thousands):


	December 31,
	2018		2017
Due in one year or less	$	797,649	$	2,042,673
Due after one year through three years		201,826		902,938

Total	$	999,475	$	2,945,611