| Summary of Valuation of Investments and Financial Instruments Pricing Levels |
The following tables summarize the valuation of our investments and
financial instruments by the above pricing levels as of the
valuation dates listed:
|
|
|
|
|
|
|
|
|
|
|
|
|
| |
|
|
|
|
December 31, 2016 |
|
| |
|
Total |
|
|
(Level 1) |
|
|
(Level 2) |
|
| |
|
|
|
|
(Thousands of
dollars) |
|
|
Investments:
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Money market mutual funds
|
|
$ |
18,118 |
|
|
$ |
18,118 |
|
|
$ |
— |
|
|
Commercial paper
|
|
|
27,867 |
|
|
|
— |
|
|
|
27,867 |
|
|
U.S. government agencies
|
|
|
13,263 |
|
|
|
— |
|
|
|
13,263 |
|
|
Corporate bonds and notes
|
|
|
243,582 |
|
|
|
— |
|
|
|
243,582 |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
302,830 |
|
|
|
18,118 |
|
|
|
284,712 |
|
|
|
|
|
|
Deferred compensation plan assets
|
|
|
2,394 |
|
|
|
2,394 |
|
|
|
— |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Total
|
|
$ |
305,224 |
|
|
$ |
20,512 |
|
|
$ |
284,712 |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| |
|
|
|
|
December 31, 2015 |
|
| |
|
Total |
|
|
(Level 1) |
|
|
(Level 2) |
|
| |
|
|
|
|
(Thousands of
dollars) |
|
|
Investments:
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Money market mutual funds
|
|
$ |
18,181 |
|
|
$ |
18,181 |
|
|
$ |
— |
|
|
Commercial paper
|
|
|
5,981 |
|
|
|
— |
|
|
|
5,981 |
|
|
U.S. government agencies
|
|
|
11,469 |
|
|
|
— |
|
|
|
11,469 |
|
|
Corporate bonds and notes
|
|
|
264,228 |
|
|
|
— |
|
|
|
264,228 |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
299,859 |
|
|
|
18,181 |
|
|
|
281,678 |
|
|
|
|
|
|
Deferred compensation plan assets
|
|
|
2,294 |
|
|
|
2,294 |
|
|
|
— |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Total
|
|
$ |
302,153 |
|
|
$ |
20,475 |
|
|
$ |
281,678 |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| Summary of Combined Fair Value of Assets that Incurred Impairments |
The below table summarizes the combined fair value of the assets
that incurred impairments during the years ended December 31,
2016, 2015 and 2014, along with the amount of the impairment. The
impairment charges were recorded in Impairment of assets. See Note
1 for additional information.
|
|
|
|
|
|
|
|
|
|
|
|
|
| |
|
Year Ended
December 31, |
|
| |
|
2016 |
|
|
2015 |
|
|
2014 |
|
| |
|
(Thousands of
dollars) |
|
|
Amount of impairment incurred
|
|
$ |
407 |
|
|
$ |
— |
|
|
$ |
10,508 |
|
|
Combined fair value of assets incurring impairment, after
impairment charges
|
|
$ |
1,380 |
|
|
$ |
— |
|
|
$ |
6,000 |
|
|