Financial Instruments (Investment and Derivative Information) (Details) - USD ($) $ in Thousands |
3 Months Ended | 9 Months Ended | ||
|---|---|---|---|---|
Sep. 30, 2016 |
Sep. 30, 2015 |
Sep. 30, 2016 |
Sep. 30, 2015 |
|
| Foreign Exchange Contract | ||||
| Fair Value Measurements | ||||
| Assets related to derivative instruments | $ 0 | $ 0 | ||
| Liabilities related to derivative instruments | 0 | 0 | ||
| Notional principal amount of foreign exchange contracts | 9,900 | 9,900 | ||
| Foreign Exchange Contract | Other income (expense), net | Not Designated as Hedging Instrument | ||||
| Fair Value Measurements | ||||
| Foreign exchange contracts | $ (60) | $ 418 | $ (17) | $ 318 |
| Minimum | ||||
| Fair Value Measurements | ||||
| Maturity period of long-term investments | 1 year | |||
| Maximum | ||||
| Fair Value Measurements | ||||
| Maturity period of long-term investments | 2 years | |||