Fair Value of Financial Instruments (Narrative) (Details) - USD ($) $ in Millions |
Dec. 31, 2015 |
Dec. 31, 2014 |
|---|---|---|
| Level 1 | Money market funds | ||
| Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] | ||
| Money market fund, fair value | $ 31.6 | $ 21.9 |