Annual report pursuant to Section 13 and 15(d)

Summary of Significant Accounting Policies - Additional Information (Detail)

v3.3.1.900
Summary of Significant Accounting Policies - Additional Information (Detail)
 12 Months Ended
Dec. 31, 2015
USD ($)
Segment
Dec. 31, 2014
USD ($)
Dec. 31, 2013
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  
Impairment loss on goodwill $ 0 $ 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.    
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%    
Minimum [Member]      
Summary Of Significant Accounting Policies [Line Items]      
Finite-lived intangible asset, useful life 3 years    
Percentage of taxable income distributed to stockholders 90.00%    
Maximum [Member]      
Summary Of Significant Accounting Policies [Line Items]      
Finite-lived intangible asset, useful life 15 years