|
Fair Value Measurements - Schedule of Fair Value Hierarchy of Financial Assets Carried at Fair Value and Measured on Recurring Basis (Detail) (USD $)
In Thousands, unless otherwise specified
|
Mar. 31, 2015
|
Dec. 31, 2014
|
| Available-for-sale securities: |
|
|
| Debt securities |
$ 246,797 |
$ 251,620 |
| Equity securities |
2,789 |
3,234 |
| Total available-for-sale investments |
249,586 |
254,854 |
| Fair value measurements, Recurring |
|
|
| Cash equivalents: |
|
|
| Total cash equivalents |
9,709 |
14,486 |
| Available-for-sale securities: |
|
|
| Debt securities |
246,797 |
251,620 |
| Equity securities |
2,789 |
3,234 |
| Total available-for-sale investments |
249,586 |
254,854 |
| Total assets at fair value |
259,295 |
269,340 |
| Fair value measurements, Recurring | U.S. government securities |
|
|
| Available-for-sale securities: |
|
|
| Debt securities |
110,030 |
100,818 |
| Fair value measurements, Recurring | International government securities |
|
|
| Available-for-sale securities: |
|
|
| Debt securities |
5,257 |
6,560 |
| Fair value measurements, Recurring | Commercial paper |
|
|
| Available-for-sale securities: |
|
|
| Debt securities |
20,387 |
24,589 |
| Fair value measurements, Recurring | Time deposits |
|
|
| Available-for-sale securities: |
|
|
| Debt securities |
28,272 |
30,759 |
| Fair value measurements, Recurring | Corporate bonds |
|
|
| Available-for-sale securities: |
|
|
| Debt securities |
|
1,528 |
| Fair value measurements, Recurring | Taxable municipal bonds |
|
|
| Available-for-sale securities: |
|
|
| Debt securities |
82,851 |
87,366 |
| Fair value measurements, Recurring | Money market and other funds |
|
|
| Cash equivalents: |
|
|
| Total cash equivalents |
2,954 |
8,490 |
| Fair value measurements, Recurring | Commercial paper |
|
|
| Cash equivalents: |
|
|
| Total cash equivalents |
6,000 |
|
| Fair value measurements, Recurring | Time deposits |
|
|
| Cash equivalents: |
|
|
| Total cash equivalents |
250 |
1,242 |
| Fair value measurements, Recurring | Taxable municipal bonds |
|
|
| Cash equivalents: |
|
|
| Total cash equivalents |
505 |
4,754 |
| Fair value measurements, Recurring | Quoted prices in active markets using identical assets (Level 1) |
|
|
| Cash equivalents: |
|
|
| Total cash equivalents |
0 |
0 |
| Available-for-sale securities: |
|
|
| Debt securities |
0 |
0 |
| Equity securities |
2,789 |
3,234 |
| Total available-for-sale investments |
2,789 |
3,234 |
| Total assets at fair value |
2,789 |
3,234 |
| Fair value measurements, Recurring | Quoted prices in active markets using identical assets (Level 1) | U.S. government securities |
|
|
| Available-for-sale securities: |
|
|
| Debt securities |
0 |
0 |
| Fair value measurements, Recurring | Quoted prices in active markets using identical assets (Level 1) | International government securities |
|
|
| Available-for-sale securities: |
|
|
| Debt securities |
0 |
0 |
| Fair value measurements, Recurring | Quoted prices in active markets using identical assets (Level 1) | Commercial paper |
|
|
| Available-for-sale securities: |
|
|
| Debt securities |
0 |
0 |
| Fair value measurements, Recurring | Quoted prices in active markets using identical assets (Level 1) | Time deposits |
|
|
| Available-for-sale securities: |
|
|
| Debt securities |
0 |
0 |
| Fair value measurements, Recurring | Quoted prices in active markets using identical assets (Level 1) | Corporate bonds |
|
|
| Available-for-sale securities: |
|
|
| Debt securities |
|
0 |
| Fair value measurements, Recurring | Quoted prices in active markets using identical assets (Level 1) | Taxable municipal bonds |
|
|
| Available-for-sale securities: |
|
|
| Debt securities |
0 |
0 |
| Fair value measurements, Recurring | Quoted prices in active markets using identical assets (Level 1) | Money market and other funds |
|
|
| Cash equivalents: |
|
|
| Total cash equivalents |
0 |
0 |
| Fair value measurements, Recurring | Quoted prices in active markets using identical assets (Level 1) | Commercial paper |
|
|
| Cash equivalents: |
|
|
| Total cash equivalents |
0 |
|
| Fair value measurements, Recurring | Quoted prices in active markets using identical assets (Level 1) | Time deposits |
|
|
| Cash equivalents: |
|
|
| Total cash equivalents |
0 |
0 |
| Fair value measurements, Recurring | Quoted prices in active markets using identical assets (Level 1) | Taxable municipal bonds |
|
|
| Cash equivalents: |
|
|
| Total cash equivalents |
0 |
0 |
| Fair value measurements, Recurring | Significant other observable inputs (Level 2) |
|
|
| Cash equivalents: |
|
|
| Total cash equivalents |
9,709 |
14,486 |
| Available-for-sale securities: |
|
|
| Debt securities |
246,797 |
251,620 |
| Equity securities |
0 |
0 |
| Total available-for-sale investments |
246,797 |
251,620 |
| Total assets at fair value |
256,506 |
266,106 |
| Fair value measurements, Recurring | Significant other observable inputs (Level 2) | U.S. government securities |
|
|
| Available-for-sale securities: |
|
|
| Debt securities |
110,030 |
100,818 |
| Fair value measurements, Recurring | Significant other observable inputs (Level 2) | International government securities |
|
|
| Available-for-sale securities: |
|
|
| Debt securities |
5,257 |
6,560 |
| Fair value measurements, Recurring | Significant other observable inputs (Level 2) | Commercial paper |
|
|
| Available-for-sale securities: |
|
|
| Debt securities |
20,387 |
24,589 |
| Fair value measurements, Recurring | Significant other observable inputs (Level 2) | Time deposits |
|
|
| Available-for-sale securities: |
|
|
| Debt securities |
28,272 |
30,759 |
| Fair value measurements, Recurring | Significant other observable inputs (Level 2) | Corporate bonds |
|
|
| Available-for-sale securities: |
|
|
| Debt securities |
|
1,528 |
| Fair value measurements, Recurring | Significant other observable inputs (Level 2) | Taxable municipal bonds |
|
|
| Available-for-sale securities: |
|
|
| Debt securities |
82,851 |
87,366 |
| Fair value measurements, Recurring | Significant other observable inputs (Level 2) | Money market and other funds |
|
|
| Cash equivalents: |
|
|
| Total cash equivalents |
2,954 |
8,490 |
| Fair value measurements, Recurring | Significant other observable inputs (Level 2) | Commercial paper |
|
|
| Cash equivalents: |
|
|
| Total cash equivalents |
6,000 |
|
| Fair value measurements, Recurring | Significant other observable inputs (Level 2) | Time deposits |
|
|
| Cash equivalents: |
|
|
| Total cash equivalents |
250 |
1,242 |
| Fair value measurements, Recurring | Significant other observable inputs (Level 2) | Taxable municipal bonds |
|
|
| Cash equivalents: |
|
|
| Total cash equivalents |
505 |
4,754 |
| Fair value measurements, Recurring | Significant unobservable inputs (Level 3) |
|
|
| Cash equivalents: |
|
|
| Total cash equivalents |
0 |
0 |
| Available-for-sale securities: |
|
|
| Debt securities |
0 |
0 |
| Equity securities |
0 |
0 |
| Total available-for-sale investments |
0 |
0 |
| Total assets at fair value |
0 |
0 |
| Fair value measurements, Recurring | Significant unobservable inputs (Level 3) | U.S. government securities |
|
|
| Available-for-sale securities: |
|
|
| Debt securities |
0 |
0 |
| Fair value measurements, Recurring | Significant unobservable inputs (Level 3) | International government securities |
|
|
| Available-for-sale securities: |
|
|
| Debt securities |
0 |
0 |
| Fair value measurements, Recurring | Significant unobservable inputs (Level 3) | Commercial paper |
|
|
| Available-for-sale securities: |
|
|
| Debt securities |
0 |
0 |
| Fair value measurements, Recurring | Significant unobservable inputs (Level 3) | Time deposits |
|
|
| Available-for-sale securities: |
|
|
| Debt securities |
0 |
0 |
| Fair value measurements, Recurring | Significant unobservable inputs (Level 3) | Corporate bonds |
|
|
| Available-for-sale securities: |
|
|
| Debt securities |
|
0 |
| Fair value measurements, Recurring | Significant unobservable inputs (Level 3) | Taxable municipal bonds |
|
|
| Available-for-sale securities: |
|
|
| Debt securities |
0 |
0 |
| Fair value measurements, Recurring | Significant unobservable inputs (Level 3) | Money market and other funds |
|
|
| Cash equivalents: |
|
|
| Total cash equivalents |
0 |
0 |
| Fair value measurements, Recurring | Significant unobservable inputs (Level 3) | Commercial paper |
|
|
| Cash equivalents: |
|
|
| Total cash equivalents |
0 |
|
| Fair value measurements, Recurring | Significant unobservable inputs (Level 3) | Time deposits |
|
|
| Cash equivalents: |
|
|
| Total cash equivalents |
0 |
0 |
| Fair value measurements, Recurring | Significant unobservable inputs (Level 3) | Taxable municipal bonds |
|
|
| Cash equivalents: |
|
|
| Total cash equivalents |
$ 0 |
$ 0 |