Stockholders' Equity/(Deficit) - Cash Dividends Paid (Details) - $ / shares |
3 Months Ended | 12 Months Ended | |||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Dec. 31, 2017 |
Sep. 30, 2017 |
Jun. 30, 2017 |
Mar. 31, 2017 |
Dec. 31, 2016 |
Sep. 30, 2016 |
Jun. 30, 2016 |
Mar. 31, 2016 |
Dec. 31, 2015 |
Sep. 30, 2015 |
Jun. 30, 2015 |
Mar. 31, 2015 |
Dec. 31, 2017 |
Dec. 31, 2016 |
Dec. 31, 2015 |
|
| Dividends Declared [Abstract] | |||||||||||||||
| Cash dividends declared per common share (USD per share) | $ 0.175 | $ 0.175 | $ 0.175 | $ 0.175 | $ 0.16 | $ 0.16 | $ 0.16 | $ 0.16 | $ 0.155 | $ 0.155 | $ 0.155 | $ 0.155 | $ 0.7 | $ 0.64 | $ 0.62 |