Convertible Subordinated Notes Convertible Subordinated Notes (Narrative) (Details) (Details) $ / shares in Units, $ in Thousands |
3 Months Ended | 9 Months Ended | ||||
|---|---|---|---|---|---|---|
Jun. 30, 2017 |
Mar. 19, 2014
$ / shares
|
Sep. 30, 2017
USD ($)
$ / shares
|
Sep. 30, 2016
USD ($)
|
Sep. 30, 2017
USD ($)
$ / shares
|
Sep. 30, 2016
USD ($)
|
|
| Debt Instrument [Line Items] | ||||||
| Amortization of Debt Issuance Costs | $ 614 | $ 622 | ||||
| Convertible Subordinated Notes [Member] | ||||||
| Debt Instrument [Line Items] | ||||||
| Debt Instrument, Convertible, Conversion Ratio | 44.5392 | 44.3169 | ||||
| Long-term Debt, Fair Value | $ 179,900 | 179,900 | ||||
| Interest Expense, Debt | 1,000 | $ 1,000 | 3,000 | 3,000 | ||
| Amortization of Debt Issuance Costs | 100 | 100 | 400 | 400 | ||
| Accretion of discount, convertible subordinated notes | $ 1,100 | $ 1,000 | $ 3,200 | $ 2,900 | ||
| Debt instrument, convertible, conversion price (in dollars per share) | $ / shares | $ 22.56 | $ 22.45 | $ 22.45 | |||
| Effective interest rate percentage | 2.75% | 6.75% | 2.75% | 6.75% | ||