Quarterly report pursuant to Section 13 or 15(d)

Commitment and Contingencies - Additional Information (Detail)

v3.20.2
Commitment and Contingencies - Additional Information (Detail)
$ in Thousands
3 Months Ended 6 Months Ended
Mar. 31, 2020
USD ($)
Property
Jun. 30, 2020
USD ($)
Jun. 30, 2019
USD ($)
Jun. 30, 2020
USD ($)
Jun. 30, 2019
USD ($)
Dec. 31, 2019
USD ($)
Commitment And Contingencies [Line Items]            
Operating lease, aggregate right-of-use assets   $ 19,600   $ 19,600   $ 20,200
Operating Lease, Right-of-Use Asset, Statement of Financial Position [Extensible List]   us-gaap:OtherAssetsMember   us-gaap:OtherAssetsMember   us-gaap:OtherAssetsMember
Operating lease liabilities   $ 19,000   $ 19,000   $ 19,900
Operating Lease, Liability, Statement of Financial Position [Extensible List]   us-gaap:AccountsPayableAndAccruedLiabilitiesMember   us-gaap:AccountsPayableAndAccruedLiabilitiesMember   us-gaap:AccountsPayableAndAccruedLiabilitiesMember
Operating lease expenses   $ 500 $ 600 $ 1,000 $ 1,300  
Weighted average remaining lease term   10 years 9 months 18 days   10 years 9 months 18 days    
Weighted average discount rate   4.60%   4.60%    
Operating lease commitments   $ 24,331   $ 24,331    
Expansion and enhancement contracts       $ 17,300    
Self-storage Facilities [Member]            
Commitment And Contingencies [Line Items]            
Number of storage facilities to be sold | Property 1          
Sale price of storage facilities $ 19,000