Income Taxes - Federal Income Tax Treatment of Share Distributions (Detail) - Common Stock - $ / shares	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Income Tax [Line Items]
Ordinary Income	$ 0.2629	$ 0.4412	$ 0.3088
Unrecaptured Section 1250 Gain	0.1241	0.0000	0.0000
Distributions Per Common Share	$ 0.3870	$ 0.4412	$ 0.3088
Ordinary Income as a Percentage of Distribution	67.93%	100.00%	100.00%
Unrecaptured Section 1250 Gain as a Percentage of Distribution	32.07%	0.00%	0.00%
Common Distributions Percentage	100.00%	100.00%	100.00%