Commitment and Contingencies - Additional Information (Detail) $ in Thousands			1 Months Ended	3 Months Ended		6 Months Ended
	Jul. 13, 2022 Property	Jul. 01, 2022 USD ($)	Jul. 31, 2022 USD ($) Property	Jun. 30, 2022 USD ($)	Jun. 30, 2021 USD ($)	Jun. 30, 2022 USD ($) Property	Jun. 30, 2021 USD ($)	Dec. 31, 2021 USD ($)
Commitment And Contingencies [Line Items]
Operating lease, aggregate right-of-use assets				$ 18,600		$ 18,600		$ 19,500
Operating Lease, Right-of-Use Asset, Statement of Financial Position [Extensible List]				Other assets		Other assets		Other assets
Operating lease liabilities				$ 18,000		$ 18,000		$ 19,200
Operating Lease, Liability, Statement of Financial Position [Extensible List]				us-gaap:AccountsPayableAndAccruedLiabilitiesMember		us-gaap:AccountsPayableAndAccruedLiabilitiesMember		us-gaap:AccountsPayableAndAccruedLiabilitiesMember
Operating lease expenses				$ 700	$ 600	$ 1,300	$ 1,200
Weighted average remaining lease term				9 years 10 months 24 days		9 years 10 months 24 days
Weighted average discount rate				4.61%		4.61%
Operating lease commitments				$ 22,863		$ 22,863
Number of storage facilities acquired | Property						31
Purchase Price						$ 614,091
Expansion and enhancement contracts						66,500
Subsequent Event [Member]
Commitment And Contingencies [Line Items]
Purchase Price		$ 140,100
Self-storage Facilities [Member]
Commitment And Contingencies [Line Items]
Purchase price of business to be acquired						$ 137,400
Number of storage facilities acquired | Property						7
Number of storage facilities to be acquired | Property						6
Self-storage Facilities [Member] | Subsequent Event [Member]
Commitment And Contingencies [Line Items]
Purchase price of business to be acquired			$ 20,000
Number of storage facilities acquired | Property	1		1