| Investment securities, available-for-sale |
As of June 30, 2013 and December 31, 2012, the gross unrealized losses and fair values of available-for-sale investment securities that were in unrealized loss positions were as follows: | | | | | | | | | | | | | | | | | | | | | | | | | | Less than 12 months | | 12 months or more | | Total fair value | | Total unrealized loss | | Fair value | | Unrealized loss | | Fair value | | Unrealized loss | | | June 30, 2013 | (In thousands) | Corporate bonds | $ | 19,226 |
| | $ | (25 | ) | | $ | — |
| | $ | — |
| | $ | 19,226 |
| | $ | (25 | ) | Commercial paper | 8,384 |
| | (2 | ) | | — |
| | — |
| | 8,384 |
| | (2 | ) | Agency securities | 13,488 |
| | (18 | ) | | — |
| | — |
| | 13,488 |
| | (18 | ) | Mortgage-backed securities | 1,147 |
| | (59 | ) | | — |
| | — |
| | 1,147 |
| | (59 | ) | Municipal bonds | 11,599 |
| | (30 | ) | | — |
| | — |
| | 11,599 |
| | (30 | ) | Asset-backed securities | 9,846 |
| | (21 | ) | | — |
| | — |
| | $ | 9,846 |
| | $ | (21 | ) | Total investment securities | $ | 63,690 |
| | $ | (155 | ) | | $ | — |
| | $ | — |
| | $ | 63,690 |
| | $ | (155 | ) | | | | | | | | | | | | | December 31, 2012 | | | | | | | | | | | | Corporate bonds | $ | 6,138 |
| | $ | (2 | ) | | $ | — |
| | $ | — |
| | $ | 6,138 |
| | $ | (2 | ) | Commercial paper | 6,390 |
| | (2 | ) | | — |
| | — |
| | 6,390 |
| | (2 | ) | Agency securities | 6,302 |
| | (1 | ) | | — |
| | — |
| | 6,302 |
| | (1 | ) | Municipal bonds | 1,602 |
| | (3 | ) | | — |
| | — |
| | 1,602 |
| | (3 | ) | Total investment securities | $ | 20,432 |
| | $ | (8 | ) | | $ | — |
| | $ | — |
| | $ | 20,432 |
| | $ | (8 | ) |
Our available-for-sale investment securities were as follows: | | | | | | | | | | | | | | | | | | Amortized cost | | Gross unrealized gains | | Gross unrealized losses | | Fair value | June 30, 2013 | (In thousands) | Corporate bonds | $ | 38,961 |
| | $ | 29 |
| | $ | (25 | ) | | $ | 38,965 |
| Commercial paper | 58,949 |
| | 23 |
| | (2 | ) | | 58,970 |
| Negotiable certificate of deposit | 4,400 |
| | 9 |
| | — |
| | 4,409 |
| U.S. Treasury notes | 2,301 |
| | 3 |
| | — |
| | 2,304 |
| Agency securities | 26,515 |
| | 7 |
| | (18 | ) | | 26,504 |
| Mortgage-backed securities | 1,206 |
| | — |
| | (59 | ) | | 1,147 |
| Municipal bonds | 19,600 |
| | 20 |
| | (30 | ) | | 19,590 |
| Asset-backed securities | 20,590 |
| | 9 |
| | (21 | ) | | 20,578 |
| Total investment securities | $ | 172,522 |
| | $ | 100 |
| | $ | (155 | ) | | $ | 172,467 |
| | | | | | | | | December 31, 2012 | | | | | | | | Corporate bonds | $ | 37,320 |
| | $ | 39 |
| | $ | (2 | ) | | $ | 37,357 |
| Commercial paper | 55,733 |
| | 17 |
| | (2 | ) | | 55,748 |
| Negotiable certificate of deposit | 4,400 |
| | 14 |
| | — |
| | 4,414 |
| U.S. Treasury notes | 22,258 |
| | 9 |
| | — |
| | 22,267 |
| Agency securities | 25,845 |
| | 23 |
| | (1 | ) | | 25,867 |
| Municipal bonds | 11,528 |
| | 43 |
| | (3 | ) | | 11,568 |
| Asset-backed securities | 26,533 |
| | 33 |
| | — |
| | 26,566 |
| Total investment securities | $ | 183,617 |
| | $ | 178 |
| | $ | (8 | ) | | $ | 183,787 |
|
|
| Investments Classified by Contractual Maturity Date |
As of June 30, 2013, the contractual maturities of our available-for-sale investment securities were as follows: | | | | | | | | | | Amortized cost | | Fair value | | (In thousands) | Due in one year or less | $ | 103,666 |
| | $ | 103,713 |
| Due after one year through five years | 45,511 |
| | 45,493 |
| Due after five years through ten years | 1,049 |
| | 1,049 |
| Due after ten years | 500 |
| | 487 |
| Mortgage and asset-backed securities | 21,796 |
| | 21,725 |
| Total investment securities | $ | 172,522 |
| | $ | 172,467 |
|
The expected payments on mortgage-backed and asset-backed securities may not coincide with their contractual maturities because the issuers have the right to call or prepay certain obligations. |