Stockholders' Equity - Narrative (Details) - USD ($) $ / shares in Units, $ in Millions |
3 Months Ended | 6 Months Ended | |
|---|---|---|---|
Apr. 14, 2015 |
Jun. 30, 2015 |
Jun. 30, 2015 |
|
| Subsidiary, Sale of Stock [Line Items] | |||
| Issuance of common shares (in shares) | 23,000,000 | ||
| Price per share (in USD per share) | $ 11.85 | ||
| Proceeds from issuance of common stock | $ 272.6 | ||
| Net proceeds from common stock offering | $ 268.8 | ||
| Payment of commissions and other issuance costs | $ 1.3 | ||
| Weighted Average | |||
| Subsidiary, Sale of Stock [Line Items] | |||
| Price per share (in USD per share) | $ 12.07 | $ 12.07 | |
| Underwriter Option | |||
| Subsidiary, Sale of Stock [Line Items] | |||
| Issuance of common shares (in shares) | 3,000,000 | ||
| ATM Program | |||
| Subsidiary, Sale of Stock [Line Items] | |||
| Issuance of common shares (in shares) | 0 | 6,600,000 | |
| Proceeds from issuance of common stock | $ 79.8 | ||
| Net proceeds from common stock offering | 78.5 | ||
| Capacity available | $ 103.6 | $ 103.6 |