NET INCOME PER COMMON SHARE - Additional Information (Details) |
3 Months Ended | 12 Months Ended |
|---|---|---|
Mar. 31, 2018 |
Dec. 31, 2017 |
|
| Cumulative Redeemable Preferred Stock, Series E [Member] | ||
| Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items] | ||
| Preferred stock, dividend rate | 7.50% | 7.50% |