Borrowings (Details) - USD ($) $ in Millions |
3 Months Ended | ||
|---|---|---|---|
Mar. 31, 2018 |
Mar. 31, 2017 |
Dec. 31, 2017 |
|
| Long-term borrowings | |||
| Long-term debt | $ 194.3 | $ 192.6 | |
| Less: current maturities | 0.0 | 0.0 | |
| Long-term portion | 194.3 | 192.6 | |
| Long-term Debt, Maturities, Repayments of Principal, Remainder of Fiscal Year | 0.0 | ||
| Long-term Debt, Maturities, Repayments of Principal in Year Two | 0.0 | ||
| Long-term Debt, Maturities, Repayments of Principal in Year Three | 0.0 | ||
| Supplemental Cash Flow Information, Interest Paid | |||
| Interest Paid, Net | 0.4 | $ 1.5 | |
| Convertible Debt | Convertible Notes Due Twenty Twenty One | |||
| Debt Instrument | |||
| Debt Instrument, Unamortized Discount | 28.9 | 30.6 | |
| Long-term borrowings | |||
| Convertible Notes Payable | 143.6 | 141.9 | |
| Long-term Debt, Maturities, Repayments of Principal in Year Four | 172.5 | ||
| Line of Credit | Credit Facility due October 11, 2022 | |||
| Long-term borrowings | |||
| Long-term Line of Credit | 50.7 | $ 50.7 | |
| Long-term Debt, Maturities, Repayments of Principal in Year Five | $ 50.7 | ||