Marketable Securities (Tables)

6 Months Ended

Jun. 30, 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):


	June 30, 2018
	Amortized Cost		Unrealized Gain		Unrealized Loss			Fair Value
U.S. Treasury securities	$	239,150	$	3	$	(1,394	)	$	237,759
Foreign government securities		2,992		—		(38	)		2,954
Corporate debt securities		1,202,456		384		(4,291	)		1,198,549
Time deposits		238,315		—		(1	)		238,314
Equity securities		77		70		—			147

Total	$	1,682,990	$	457	$	(5,724	)	$	1,677,723

Amounts included in:
Cash equivalents	$	171,433	$	1	$	—		$	171,434
Investments		1,511,557		456		(5,724	)		1,506,289

Total	$	1,682,990	$	457	$	(5,724	)	$	1,677,723


	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):


	June 30, 2018		December 31, 2017
Due in one year or less	$	1,002,140	$	1,722,553
Due after one year through three years		437,122		851,547

Total	$	1,439,262	$	2,574,100