Long-Term Debt - Convertible Senior Notes (Details)
|
3 Months Ended |
|
|
Mar. 31, 2016
USD ($)
day
$ / shares
|
May. 05, 2015
USD ($)
|
| Debt Instrument [Line Items] |
|
|
| Debt Instrument, Fair Value Disclosure |
$ 232,600,000
|
|
| Senior Notes [Member] |
|
|
| Debt Instrument [Line Items] |
|
|
| Stated interest rate |
|
2.50%
|
| Convertible debt |
|
$ 223,100,000
|
| Conversion ratio |
25.5428
|
|
| Conversion price (usd per share) | $ / shares |
$ 39.15
|
|
| Convertible senior notes, principal amount |
$ 230,000,000
|
|
| Unamortized debt discount |
(26,428,209)
|
|
| Unamortized debt issuance costs |
(5,226,948)
|
|
| Convertible senior notes, net |
198,344,843
|
|
| Contractual coupon interest |
1,400,000
|
|
| Debt discount amortization |
1,400,000
|
|
| Debt issuance cost amortization |
$ 300,000
|
|
| Senior Notes [Member] | Debt Instrument, Redemption, Period One |
|
|
| Debt Instrument [Line Items] |
|
|
| Threshold trading days | day |
20
|
|
| Threshold consecutive trading days |
30 days
|
|
| Stock price to conversion price trigger |
130.00%
|
|
| Senior Notes [Member] | Debt Instrument, Redemption, Period Two |
|
|
| Debt Instrument [Line Items] |
|
|
| Threshold consecutive trading days |
5 days
|
|
| Stock price to conversion price trigger |
98.00%
|
|
| Senior Notes [Member] | Debt Instrument, Redemption, Fundamental Change |
|
|
| Debt Instrument [Line Items] |
|
|
| Stock price to conversion price trigger |
100.00%
|
|
| Maximum | Senior Notes [Member] | Debt Instrument, Redemption, Fundamental Change |
|
|
| Debt Instrument [Line Items] |
|
|
| Conversion ratio |
34.4827
|
|
| Level 2 | Senior Notes [Member] |
|
|
| Debt Instrument [Line Items] |
|
|
| Straight debt borrowing rate |
5.75%
|
|
| Fair value of liability component |
$ 198,500,000
|
|
| Fair value of equity component |
$ 31,500,000
|
|
| Effective interest rate |
6.33%
|
|
| Discount amortization period |
5 years
|
|