STOCKHOLDERS' EQUITY - Common Stock Dividend Distributions (Details) - USD ($) |
12 Months Ended | ||||
|---|---|---|---|---|---|
Jan. 11, 2017 |
Mar. 20, 2014 |
Dec. 31, 2016 |
Dec. 31, 2015 |
Dec. 31, 2014 |
|
| Stockholders' Equity | |||||
| Cash distributions declared per share of common stock (in dollars per share) | $ 1.66 | $ 1.58 | $ 1.50 | ||
| Common shares issued under the Distribution Reinvestment Plan | 142,000 | 197,000 | 227,000 | ||
| Maximum aggregate sales price of shares to be sold under an Equity Offering Sales Agreement | $ 38,360,000 | ||||
| Number of shares sold (in shares) | 27,800 | 1,079,862 | 295,190 | ||
| Proceeds from sale of shares, net of commission and before offering costs | $ 692,000 | $ 25,947,000 | $ 6,581,000 | ||
| Payment of commissions on sale of shares | $ 7,000 | 262,000 | 66,000 | ||
| Payment of Offering Costs on Sale of Shares | $ 160,000 | $ 124,000 | |||
| Maximum | |||||
| Stockholders' Equity | |||||
| Discount rate (as a percent) | 5.00% | ||||