Quarterly report pursuant to Section 13 or 15(d)

Summary of Significant Accounting Policies - Additional Information (Detail)

v3.3.0.814
Summary of Significant Accounting Policies - Additional Information (Detail)
3 Months Ended 9 Months Ended
Sep. 30, 2015
USD ($)
Sep. 30, 2014
USD ($)
Sep. 30, 2015
USD ($)
Segment
Sep. 30, 2014
USD ($)
Dec. 31, 2014
USD ($)
Summary Of Significant Accounting Policies [Line Items]          
Financing receivable, past due     90 days    
Cash and cash equivalents original maturity period     3 months    
Impairment of equity method investments $ 0   $ 0    
Real estate investment description     To qualify as a REIT, we must meet a number of organizational and operational requirements, including a requirement that we currently distribute at least 90% of our net taxable income, excluding capital gains, to our shareholders.    
Income tax examination, description     We have no examinations in progress, none are expected at this time, and years 2012 through 2014 are open.    
Uncertain tax positions 0   $ 0   $ 0
Accrued interest and penalties 0   0   $ 0
Interest and penalties recognized during the period $ 0 $ 0 $ 0 $ 0  
Number of segment reported | Segment     1    
2013 Plan [Member] | Performance Based Restricted Stock Award [Member]          
Summary Of Significant Accounting Policies [Line Items]          
Stock-based award vesting minimum percentage     0.00%    
Stock-based award vesting maximum percentage     150.00%    
Stock-based award, range of vesting percentage description     The award earned is generally between 0% and 150% of the initial target, depending on the extent to which the performance target are met.    
Strong Upwind Holdings LLC [Member]          
Summary Of Significant Accounting Policies [Line Items]          
Ownership percentage 50.00%   50.00%    
Minimum [Member]          
Summary Of Significant Accounting Policies [Line Items]          
Percentage of taxable income distributed to stockholders     90.00%