Equity - Monthly Distributions Declared and Paid by Company's Board of Directors (Detail) - $ / shares |
3 Months Ended | |||||||
|---|---|---|---|---|---|---|---|---|
Mar. 31, 2016 |
Feb. 29, 2016 |
Feb. 02, 2016 |
Mar. 31, 2015 |
Feb. 27, 2015 |
Feb. 03, 2015 |
Mar. 31, 2016 |
Mar. 31, 2015 |
|
| Class of Stock [Line Items] | ||||||||
| Distributions per Common Share | $ 0.120 | $ 0.105 | ||||||
| Monthly Distribution One [Member] | ||||||||
| Class of Stock [Line Items] | ||||||||
| Dividend Declaration Date | Jan. 12, 2016 | Jan. 13, 2015 | ||||||
| Record Date | Jan. 22, 2016 | Jan. 23, 2015 | ||||||
| Dividend Payment Date | Feb. 02, 2016 | Mar. 03, 2015 | ||||||
| Distributions per Common Share | $ 0.040 | $ 0.035 | ||||||
| Monthly Distribution Two [Member] | ||||||||
| Class of Stock [Line Items] | ||||||||
| Dividend Declaration Date | Jan. 12, 2016 | Jan. 13, 2015 | ||||||
| Record Date | Feb. 18, 2016 | Feb. 18, 2015 | ||||||
| Dividend Payment Date | Feb. 29, 2016 | Feb. 27, 2015 | ||||||
| Distributions per Common Share | $ 0.040 | $ 0.035 | ||||||
| Monthly Distribution Three [Member] | ||||||||
| Class of Stock [Line Items] | ||||||||
| Dividend Declaration Date | Jan. 12, 2016 | Jan. 13, 2015 | ||||||
| Record Date | Mar. 21, 2016 | Mar. 20, 2015 | ||||||
| Dividend Payment Date | Mar. 31, 2016 | Mar. 31, 2015 | ||||||
| Distributions per Common Share | $ 0.040 | $ 0.035 | ||||||