Investments (Tables)
|
3 Months Ended |
Mar. 31, 2017 |
|---|
| Investments, Debt and Equity Securities [Abstract] |
|
| Components of Investments |
Investments consisted of the following as of March 31,
2017:
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Unrealized |
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Unrealized |
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Fair |
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| |
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Cost Basis |
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Gains |
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Losses |
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Value |
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| |
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(Thousands of dollars) |
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Investments:
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Money market mutual funds
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$ |
10,597 |
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|
$ |
— |
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|
$ |
— |
|
|
$ |
10,597 |
|
|
Commercial paper
|
|
|
27,935 |
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|
|
— |
|
|
|
(26 |
) |
|
|
27,909 |
|
|
U.S. Government agencies
|
|
|
15,305 |
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|
|
— |
|
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|
(20 |
) |
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|
15,285 |
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|
Corporate bonds and notes
|
|
|
236,525 |
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|
4 |
|
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|
(479 |
) |
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|
236,050 |
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Subtotal
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290,362 |
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|
4 |
|
|
|
(525 |
) |
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|
289,841 |
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|
Deferred compensation plan assets included in other assets
|
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|
2,500 |
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|
|
— |
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|
— |
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|
2,500 |
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|
|
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|
|
|
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|
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Total
|
|
$ |
292,862 |
|
|
$ |
4 |
|
|
$ |
(525 |
) |
|
$ |
292,341 |
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|
Investments consisted of the following as of December 31,
2016:
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| |
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Unrealized |
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Unrealized |
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Fair |
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| |
|
Cost Basis |
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|
Gains |
|
|
Losses |
|
|
Value |
|
| |
|
(Thousands of dollars) |
|
|
Investments:
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
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Money market mutual funds
|
|
$ |
18,118 |
|
|
$ |
— |
|
|
$ |
— |
|
|
$ |
18,118 |
|
|
Commercial paper
|
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|
27,906 |
|
|
|
— |
|
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|
(39 |
) |
|
|
27,867 |
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|
U.S. government agencies
|
|
|
13,295 |
|
|
|
— |
|
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|
(32 |
) |
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|
13,263 |
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|
Corporate bonds and notes
|
|
|
244,202 |
|
|
|
2 |
|
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|
(622 |
) |
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|
243,582 |
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Subtotal
|
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|
303,521 |
|
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|
2 |
|
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|
(693 |
) |
|
|
302,830 |
|
|
Deferred compensation plan assets included in other assets
|
|
|
2,394 |
|
|
|
— |
|
|
|
— |
|
|
|
2,394 |
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Total
|
|
$ |
305,915 |
|
|
$ |
2 |
|
|
$ |
(693 |
) |
|
$ |
305,224 |
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| Cost and Fair Value of Debt Investments Based on Maturities |
The following table presents the cost and fair value of our debt
investments based on maturities as of:
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March 31, 2017 |
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|
December 31, 2016 |
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Amortized |
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Fair |
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|
Amortized |
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Fair |
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| |
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Costs |
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Value |
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|
Costs |
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|
Value |
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(Thousands of dollars) |
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|
Due in one year or less
|
|
$ |
200,195 |
|
|
$ |
199,906 |
|
|
$ |
184,587 |
|
|
$ |
184,334 |
|
|
Due within two years
|
|
|
79,570 |
|
|
|
79,338 |
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|
|
100,816 |
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|
100,378 |
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Total
|
|
$ |
279,765 |
|
|
$ |
279,244 |
|
|
$ |
285,403 |
|
|
$ |
284,712 |
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| Average Coupon Rate Percentage and Average Days to Maturity of Debt |
The following table presents the average coupon rate percentage and
the average days to maturity of our debt investments as of:
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March 31, 2017 |
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|
December 31, 2016 |
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Average |
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Average |
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Average |
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|
Average |
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Coupon |
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Days To |
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|
Coupon |
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|
Days To |
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| |
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Rate (%) |
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|
Maturity |
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|
Rate (%) |
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|
Maturity |
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|
Commercial paper
|
|
|
1.035 |
|
|
|
140 |
|
|
|
1.001 |
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|
184 |
|
|
U.S. Government agencies
|
|
|
1.056 |
|
|
|
355 |
|
|
|
0.970 |
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|
400 |
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|
Corporate bonds and notes
|
|
|
1.731 |
|
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|
287 |
|
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|
1.745 |
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|
|
318 |
|
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| Investments in Continuous Unrealized Loss Position for Less Than Twelve Months |
The following table presents the fair value and unrealized losses
related to our investments that have been in a continuous
unrealized loss position for less than twelve months as of:
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|
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| |
|
March 31, 2017 |
|
|
December 31, 2016 |
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| |
|
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Unrealized |
|
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|
Unrealized |
|
| |
|
Fair Value |
|
|
Losses |
|
|
Fair Value |
|
|
Losses |
|
| |
|
(Thousands of dollars) |
|
|
Commercial paper
|
|
$ |
27,909 |
|
|
$ |
(26 |
) |
|
$ |
27,867 |
|
|
$ |
(39 |
) |
|
U.S. Government agencies
|
|
|
14,285 |
|
|
|
(20 |
) |
|
|
13,263 |
|
|
|
(32 |
) |
|
Corporate bonds and notes
|
|
|
207,512 |
|
|
|
(460 |
) |
|
|
210,836 |
|
|
|
(602 |
) |
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|
|
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Total
|
|
$ |
249,706 |
|
|
$ |
(506 |
) |
|
$ |
251,966 |
|
|
$ |
(673 |
) |
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| Investments in Continuous Unrealized Loss Position for More Than Twelve Months |
The following table presents the fair value and unrealized losses
related to our investments that have been in a continuous
unrealized loss position for more than twelve months as of:
|
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|
|
| |
|
March 31, 2017 |
|
|
December 31, 2016 |
|
| |
|
|
|
|
Unrealized |
|
|
|
|
|
Unrealized |
|
| |
|
Fair Value |
|
|
Losses |
|
|
Fair Value |
|
|
Losses |
|
| |
|
(Thousands of dollars) |
|
|
Corporate bonds and notes
|
|
$ |
20,116 |
|
|
$ |
(19 |
) |
|
$ |
24,196 |
|
|
$ |
(20 |
) |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
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Total
|
|
$ |
20,116 |
|
|
$ |
(19 |
) |
|
$ |
24,196 |
|
|
$ |
(20 |
) |
|
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