Fair Value Measurements (Narrative) (Details) |
Jun. 30, 2017
USD ($)
|
|---|---|
| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | |
| Liabilities measured at fair value | $ 0 |
| Convertible Subordinated Notes [Member] | |
| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | |
| Long-term debt measured at fair value | $ 187,600,000 |