Summary of Significant Accounting Policies - Additional Information (Detail)		3 Months Ended
	Jun. 11, 2015 JointVenture	Mar. 31, 2018 USD ($) Property JointVenture State Segment	Mar. 31, 2017 USD ($)	Dec. 31, 2017 USD ($)
Summary Of Significant Accounting Policies [Line Items]
Number of reportable segments | Segment		1
Impairment loss on real estate assets		$ 0	$ 0
Impairment loss		0	0
Restricted cash		177,419,000	113,875,000	$ 175,665,000
Prepaid rental income		$ 3,700,000
Number of wholly owned properties acquired | Property		225
Number of joint venture properties acquired | JointVenture		24
Number of states in properties located | State		49
Santa Monica, CA [Member] | ASU 2014-09 [Member]
Summary Of Significant Accounting Policies [Line Items]
Percentage of interest sold		49.90%
Interest Rate Cap [Member]
Summary Of Significant Accounting Policies [Line Items]
Interest rate caps purchased		$ 5,000,000
Derivative, term of contract		4 years
Notional amount		$ 1,261,000,000
Derivative strike rate		3.50%
Derivative gain (losses)		$ 200,000	$ (500,000)
Master Lease [Member]
Summary Of Significant Accounting Policies [Line Items]
Right to recapture property space		50.00%
Sears Holdings Corporation [Member]
Summary Of Significant Accounting Policies [Line Items]
Right to recapture property space		100.00%
Number of joint venture properties acquired | JointVenture	3
Sears Holdings Corporation [Member] | Master Lease [Member]
Summary Of Significant Accounting Policies [Line Items]
Right to recapture property space		100.00%
Restricted Cash Reserves [Member]
Summary Of Significant Accounting Policies [Line Items]
Restricted cash		$ 154,200,000
Basic Property Carrying Costs [Member]
Summary Of Significant Accounting Policies [Line Items]
Restricted cash		$ 19,500,000
Operating Partnership [Member] | ESL [Member]
Summary Of Significant Accounting Policies [Line Items]
Percentage of operating partnership interest held by parent		63.80%