Annual report pursuant to Section 13 and 15(d)

Equity Transactions - Schedule of Cash Distributions Declared and Paid (Detail)

v3.19.1
Equity Transactions - Schedule of Cash Distributions Declared and Paid (Detail) - USD ($)
$ / shares in Units, $ in Thousands
12 Months Ended
Dec. 31, 2018
Dec. 31, 2017
Dividend Payment One [Member]    
Dividends Payable [Line Items]    
Announcement Date Nov. 26, 2018 Dec. 07, 2017
Payment Date Dec. 21, 2018 Dec. 29, 2017
Amount Per Share $ 0.0650 $ 0.0650
Cash Distributed $ 1,702  
Dividend Payment Two [Member]    
Dividends Payable [Line Items]    
Announcement Date Sep. 05, 2018 Sep. 12, 2017
Payment Date Sep. 28, 2018 Sep. 29, 2017
Amount Per Share $ 0.0650 $ 0.0650
Cash Distributed $ 1,702  
Dividend Payment Three [Member]    
Dividends Payable [Line Items]    
Announcement Date May 31, 2018 Jun. 01, 2017
Payment Date Jun. 29, 2018 Jun. 30, 2017
Amount Per Share $ 0.0650 $ 0.0650
Cash Distributed $ 1,701  
Dividend Payment Four [Member]    
Dividends Payable [Line Items]    
Announcement Date Feb. 28, 2018 Mar. 09, 2017
Payment Date Mar. 28, 2018 Mar. 31, 2017
Amount Per Share $ 0.0650 $ 0.0650
Cash Distributed $ 1,701  
Dividend Payment Five [Member]    
Dividends Payable [Line Items]    
Announcement Date Dec. 07, 2017  
Payment Date Dec. 29, 2017  
Amount Per Share $ 0.0650  
Cash Distributed $ 1,701  
Dividend Payment Six [Member]    
Dividends Payable [Line Items]    
Announcement Date Sep. 12, 2017  
Payment Date Sep. 29, 2017  
Amount Per Share $ 0.0650  
Cash Distributed $ 1,701  
Dividend Payment Seven [Member]    
Dividends Payable [Line Items]    
Announcement Date Jun. 01, 2017  
Payment Date Jun. 30, 2017  
Amount Per Share $ 0.0650  
Cash Distributed $ 1,697  
Dividend Payment Eight [Member]    
Dividends Payable [Line Items]    
Announcement Date Mar. 09, 2017  
Payment Date Mar. 31, 2017  
Amount Per Share $ 0.0650  
Cash Distributed $ 1,691