XML 24 R11.htm IDEA: XBRL DOCUMENT v3.10.0.1
Fair Value Measurements
12 Months Ended
Dec. 31, 2018
Fair Value Disclosures [Abstract]  
Fair Value Measurements
Fair Value Measurements
The Company measures its financial instruments at fair value each reporting period using a fair value hierarchy that prioritizes the use of observable inputs and minimizes the use of unobservable inputs when measuring fair value. A financial instrument’s classification within the fair value hierarchy is based upon the lowest level of input that is significant to the fair value measurement.

The following table presents information about the Company’s financial instruments that are measured at fair value on a recurring basis using the input categories discussed in Note 1: 
 
As of December 31, 2018
 
Level 1
 
Level 2
 
Level 3
 
Total
 
 
 
 
 
 
 
 
Cash equivalents
 
 
 
 
 
 
 
Money market funds
$
355.5

 
$

 
$

 
$
355.5

U.S Treasury securities

 
33.4

 

 
33.4

Commercial paper

 
27.4

 

 
27.4

Total cash equivalents
$
355.5

 
$
60.8

 
$

 
$
416.3

Short-term investments
 
 
 
 
 
 
 
Corporate notes and obligations

 
269.2

 

 
269.2

U.S. Treasury securities

 
175.9

 

 
175.9

Certificates of deposit

 
70.6

 

 
70.6

U.S. agency obligations

 
37.1

 

 
37.1

Commercial paper

 
17.2

 

 
17.2

Total short-term investments

 
570.0

 

 
570.0

Total cash equivalents and short-term investments
$
355.5

 
$
630.8

 
$

 
$
986.3



The total cash equivalents held by the Company as of December 31, 2017 were $367.1 million and were entirely comprised of money market funds classified within Level 1 of the fair value hierarchy.

The Company had no transfers between levels of the fair value hierarchy.

The carrying amounts of certain financial instruments, including cash held in banks, accounts receivable and accounts payable approximate fair value due to their short-term maturities and are excluded from the fair value table above.