| Debt Securities, Noncurrent | en-US | http://www.xbrl.org/2003/role/label | http://www.xbrl.org/2003/role/link |
| Debt Securities, Noncurrent, Total | en-US | http://www.xbrl.org/2003/role/totalLabel | http://www.xbrl.org/2003/role/link |
| Amount of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale) and investment in debt security measured at amortized cost (held-to-maturity), classified as noncurrent. | en-US | http://www.xbrl.org/2003/role/documentation | http://www.xbrl.org/2003/role/link |