Leases - Summary of Termination and Redevelopement Properties (Detail)	6 Months Ended
	Jun. 30, 2018 ft²
Property Subject to or Available for Operating Lease [Line Items]
Gross leasable area	10,123,687
Lease Terminations [Member] | Master Lease [Member] | Sears Holdings Corporation [Member]
Property Subject to or Available for Operating Lease [Line Items]
Gross leasable area	2,700,000
Cullman, AL [Member] | Lease Terminations [Member] | Master Lease [Member] | Sears Holdings Corporation [Member]
Property Subject to or Available for Operating Lease [Line Items]
Gross leasable area	98,500
Notice	2016-09
Termination	2017-01
Announced Redevelopment	Q2 2017
Chicago, IL (S Kedzie) [Member] | Lease Terminations [Member] | Master Lease [Member] | Sears Holdings Corporation [Member]
Property Subject to or Available for Operating Lease [Line Items]
Gross leasable area	118,800
Notice	2016-09
Termination	2017-01
Sierra Vista, AZ [Member] | Lease Terminations [Member] | Master Lease [Member] | Sears Holdings Corporation [Member]
Property Subject to or Available for Operating Lease [Line Items]
Gross leasable area	86,100
Notice	2016-09
Termination	2017-01
Announced Redevelopment	Sold
Thornton, CO [Member] | Lease Terminations [Member] | Master Lease [Member] | Sears Holdings Corporation [Member]
Property Subject to or Available for Operating Lease [Line Items]
Gross leasable area	190,200
Notice	2016-09
Termination	2017-01
Announced Redevelopment	Q1 2017
Springfield, IL [Member] | Lease Terminations [Member] | Master Lease [Member] | Sears Holdings Corporation [Member]
Property Subject to or Available for Operating Lease [Line Items]
Gross leasable area	84,200
Notice	2016-09
Termination	2017-01
Announced Redevelopment	Q3 2016
Elkhart, IN [Member] | Lease Terminations [Member] | Master Lease [Member] | Sears Holdings Corporation [Member]
Property Subject to or Available for Operating Lease [Line Items]
Gross leasable area	86,500
Notice	2016-09
Termination	2017-01
Announced Redevelopment	Q4 2016
Merrillville, IN [Member] | Lease Terminations [Member] | Master Lease [Member] | Sears Holdings Corporation [Member]
Property Subject to or Available for Operating Lease [Line Items]
Gross leasable area	108,300
Notice	2016-09
Termination	2017-01
Announced Redevelopment	Q4 2016
Houma, LA [Member] | Lease Terminations [Member] | Master Lease [Member] | Sears Holdings Corporation [Member]
Property Subject to or Available for Operating Lease [Line Items]
Gross leasable area	96,700
Notice	2016-09
Termination	2017-01
Announced Redevelopment	Sold
New Iberia, LA [Member] | Lease Terminations [Member] | Master Lease [Member] | Sears Holdings Corporation [Member]
Property Subject to or Available for Operating Lease [Line Items]
Gross leasable area	91,700
Notice	2016-09
Termination	2017-01
Announced Redevelopment	Q2 2017
Alpena, MI [Member] | Lease Terminations [Member] | Master Lease [Member] | Sears Holdings Corporation [Member]
Property Subject to or Available for Operating Lease [Line Items]
Gross leasable area	118,200
Notice	2016-09
Termination	2017-01
Manistee, MI [Member] | Lease Terminations [Member] | Master Lease [Member] | Sears Holdings Corporation [Member]
Property Subject to or Available for Operating Lease [Line Items]
Gross leasable area	87,800
Notice	2016-09
Termination	2017-01
Sault Sainte Marie, MI [Member] | Lease Terminations [Member] | Master Lease [Member] | Sears Holdings Corporation [Member]
Property Subject to or Available for Operating Lease [Line Items]
Gross leasable area	92,700
Notice	2016-09
Termination	2017-01
Kearney, NE [Member] | Lease Terminations [Member] | Master Lease [Member] | Sears Holdings Corporation [Member]
Property Subject to or Available for Operating Lease [Line Items]
Gross leasable area	86,500
Notice	2016-09
Termination	2017-01
Announced Redevelopment	Q3 2016
Deming, NM [Member] | Lease Terminations [Member] | Master Lease [Member] | Sears Holdings Corporation [Member]
Property Subject to or Available for Operating Lease [Line Items]
Gross leasable area	96,600
Notice	2016-09
Termination	2017-01
Harlingen, TX [Member] | Lease Terminations [Member] | Master Lease [Member] | Sears Holdings Corporation [Member]
Property Subject to or Available for Operating Lease [Line Items]
Gross leasable area	91,700
Notice	2016-09
Termination	2017-01
Announced Redevelopment	Sold
Yakima, WA [Member] | Lease Terminations [Member] | Master Lease [Member] | Sears Holdings Corporation [Member]
Property Subject to or Available for Operating Lease [Line Items]
Gross leasable area	97,300
Notice	2016-09
Termination	2017-01
Announced Redevelopment	Sold
Riverton, WY [Member] | Lease Terminations [Member] | Master Lease [Member] | Sears Holdings Corporation [Member]
Property Subject to or Available for Operating Lease [Line Items]
Gross leasable area	94,800
Notice	2016-09
Termination	2017-01
Kissimmee, FL [Member] | Lease Terminations [Member] | Master Lease [Member] | Sears Holdings Corporation [Member]
Property Subject to or Available for Operating Lease [Line Items]
Gross leasable area	112,505
Notice	2017-01
Termination	2017-04
Leavenworth, KS [Member] | Lease Terminations [Member] | Master Lease [Member] | Sears Holdings Corporation [Member]
Property Subject to or Available for Operating Lease [Line Items]
Gross leasable area	76,853
Notice	2017-01
Termination	2017-04
Hopkinsville, KY [Member] | Lease Terminations [Member] | Master Lease [Member] | Sears Holdings Corporation [Member]
Property Subject to or Available for Operating Lease [Line Items]
Gross leasable area	70,326
Notice	2017-01
Termination	2017-04
Announced Redevelopment	Q1 2018
Paducah, KY [Member] | Lease Terminations [Member] | Master Lease [Member] | Sears Holdings Corporation [Member]
Property Subject to or Available for Operating Lease [Line Items]
Gross leasable area	108,244
Notice	2017-01
Termination	2017-04
Announced Redevelopment	Q3 2017
Owensboro K Y | Lease Terminations [Member] | Master Lease [Member] | Sears Holdings Corporation [Member]
Property Subject to or Available for Operating Lease [Line Items]
Gross leasable area	68,334
Notice	2017-01
Termination	2017-04
Detroit Lakes, MN [Member] | Lease Terminations [Member] | Master Lease [Member] | Sears Holdings Corporation [Member]
Property Subject to or Available for Operating Lease [Line Items]
Gross leasable area	79,102
Notice	2017-01
Termination	2017-04
Jefferson City, MO [Member] | Lease Terminations [Member] | Master Lease [Member] | Sears Holdings Corporation [Member]
Property Subject to or Available for Operating Lease [Line Items]
Gross leasable area	92,016
Notice	2017-01
Termination	2017-04
Announced Redevelopment	Q2 2017
Henderson, NV [Member] | Lease Terminations [Member] | Master Lease [Member] | Sears Holdings Corporation [Member]
Property Subject to or Available for Operating Lease [Line Items]
Gross leasable area	122,823
Notice	2017-01
Termination	2017-04
Announced Redevelopment	Q1 2017
Concord, NC [Member] | Lease Terminations [Member] | Master Lease [Member] | Sears Holdings Corporation [Member]
Property Subject to or Available for Operating Lease [Line Items]
Gross leasable area	137,499
Notice	2017-01
Termination	2017-04
Chapel Hill, OH [Member] | Lease Terminations [Member] | Master Lease [Member] | Sears Holdings Corporation [Member]
Property Subject to or Available for Operating Lease [Line Items]
Gross leasable area	187,179
Notice	2017-01
Termination	2017-04
Kenton, OH [Member] | Lease Terminations [Member] | Master Lease [Member] | Sears Holdings Corporation [Member]
Property Subject to or Available for Operating Lease [Line Items]
Gross leasable area	96,066
Notice	2017-01
Termination	2017-04
Muskogee, OK [Member] | Lease Terminations [Member] | Master Lease [Member] | Sears Holdings Corporation [Member]
Property Subject to or Available for Operating Lease [Line Items]
Gross leasable area	87,500
Notice	2017-01
Termination	2017-04
Mount Pleasant, PA [Member] | Lease Terminations [Member] | Master Lease [Member] | Sears Holdings Corporation [Member]
Property Subject to or Available for Operating Lease [Line Items]
Gross leasable area	83,536
Notice	2017-01
Termination	2017-04
Announced Redevelopment	Q2 2018
Sioux Falls, SD [Member] | Lease Terminations [Member] | Master Lease [Member] | Sears Holdings Corporation [Member]
Property Subject to or Available for Operating Lease [Line Items]
Gross leasable area	72,511
Notice	2017-01
Termination	2017-04
El Paso, TX [Member] | Lease Terminations [Member] | Master Lease [Member] | Sears Holdings Corporation [Member]
Property Subject to or Available for Operating Lease [Line Items]
Gross leasable area	103,657
Notice	2017-01
Termination	2017-04
Announced Redevelopment	Q2 2018
Layton, UT [Member] | Lease Terminations [Member] | Master Lease [Member] | Sears Holdings Corporation [Member]
Property Subject to or Available for Operating Lease [Line Items]
Gross leasable area	90,010
Notice	2017-01
Termination	2017-04
Elkins, WV [Member] | Lease Terminations [Member] | Master Lease [Member] | Sears Holdings Corporation [Member]
Property Subject to or Available for Operating Lease [Line Items]
Gross leasable area	94,885
Notice	2017-01
Termination	2017-04
Riverside, CA (Iowa Ave.) [Member]
Property Subject to or Available for Operating Lease [Line Items]
Gross leasable area	94,500
Notice	2017-01
Termination	2017-04
Platteville, WI [Member] | Lease Terminations [Member] | Master Lease [Member] | Sears Holdings Corporation [Member]
Property Subject to or Available for Operating Lease [Line Items]
Gross leasable area	94,841
Notice	2017-01
Termination	2017-04
Sarasota, FL [Member] | Lease Terminations [Member] | Master Lease [Member]
Property Subject to or Available for Operating Lease [Line Items]
Gross leasable area	204,500
Notice	2017-06
Termination	2017-10
Chicago, IL (N Harlem) [Member] | Lease Terminations [Member] | Master Lease [Member]
Property Subject to or Available for Operating Lease [Line Items]
Gross leasable area	293,700
Notice	2017-06
Termination	2017-10
Overland Park, KS [Member] | Lease Terminations [Member] | Master Lease [Member]
Property Subject to or Available for Operating Lease [Line Items]
Gross leasable area	215,000
Notice	2017-06
Termination	2017-10
Lafayette, LA [Member] | Lease Terminations [Member] | Master Lease [Member]
Property Subject to or Available for Operating Lease [Line Items]
Gross leasable area	194,900
Notice	2017-06
Termination	2017-10
Cockeysville, MD [Member] | Lease Terminations [Member] | Master Lease [Member]
Property Subject to or Available for Operating Lease [Line Items]
Gross leasable area	83,900
Notice	2017-06
Termination	2017-10
Announced Redevelopment	Q1 2017
Hagerstown, MD [member] | Lease Terminations [Member] | Master Lease [Member]
Property Subject to or Available for Operating Lease [Line Items]
Gross leasable area	107,300
Notice	2017-06
Termination	2017-10
Announced Redevelopment	Q1 2016 / Sold
Roseville, MI [Member] | Lease Terminations [Member] | Master Lease [Member]
Property Subject to or Available for Operating Lease [Line Items]
Gross leasable area	277,000
Notice	2017-06
Termination	2017-10
Announced Redevelopment	Q3 2016
Burnsville, MN [Member] | Lease Terminations [Member] | Master Lease [Member]
Property Subject to or Available for Operating Lease [Line Items]
Gross leasable area	161,700
Notice	2017-06
Termination	2017-10
Albany, NY [Member] | Lease Terminations [Member] | Master Lease [Member]
Property Subject to or Available for Operating Lease [Line Items]
Gross leasable area	216,200
Notice	2017-06
Termination	2017-10
Announced Redevelopment	Q1 2016
East Northport, NY [Member] | Lease Terminations [Member] | Master Lease [Member]
Property Subject to or Available for Operating Lease [Line Items]
Gross leasable area	187,000
Notice	2017-06
Termination	2017-10
Announced Redevelopment	Q2 2017
Johnson City, NY [Member] | Lease Terminations [Member] | Master Lease [Member]
Property Subject to or Available for Operating Lease [Line Items]
Gross leasable area	155,100
Notice	2017-06
Termination	2017-10
Olean, NY [Member] | Lease Terminations [Member] | Master Lease [Member]
Property Subject to or Available for Operating Lease [Line Items]
Gross leasable area	75,100
Notice	2017-06
Termination	2017-10
Announced Redevelopment	Q1 2017
Mentor, OH [Member] | Lease Terminations [Member] | Master Lease [Member]
Property Subject to or Available for Operating Lease [Line Items]
Gross leasable area	208,700
Notice	2017-06
Termination	2017-10
Middleburg Heights, OH [Member] | Lease Terminations [Member] | Master Lease [Member]
Property Subject to or Available for Operating Lease [Line Items]
Gross leasable area	351,600
Notice	2017-06
Termination	2017-10
Toledo, OH [Member] | Lease Terminations [Member] | Master Lease [Member]
Property Subject to or Available for Operating Lease [Line Items]
Gross leasable area	209,900
Notice	2017-06
Termination	2017-10
York, PA [Member] | Lease Terminations [Member] | Master Lease [Member]
Property Subject to or Available for Operating Lease [Line Items]
Gross leasable area	82,000
Notice	2017-06
Termination	2017-10
Warwick, RI [Member] | Lease Terminations [Member] | Master Lease [Member]
Property Subject to or Available for Operating Lease [Line Items]
Gross leasable area	169,200
Notice	2017-06
Termination	2017-10
Announced Redevelopment	Q3 2016 / Q3 2017
Friendswood, TX [Member] | Lease Terminations [Member] | Master Lease [Member]
Property Subject to or Available for Operating Lease [Line Items]
Gross leasable area	166,000
Notice	2017-06
Termination	2017-11
Westwood, TX [Member] | Lease Terminations [Member] | Master Lease [Member]
Property Subject to or Available for Operating Lease [Line Items]
Gross leasable area	215,000
Notice	2017-06
Termination	2018-01
Greendale, WI [Member] | Lease Terminations [Member] | Master Lease [Member]
Property Subject to or Available for Operating Lease [Line Items]
Gross leasable area	238,400
Notice	2017-06
Termination	2017-10
Announced Redevelopment	Q4 2017
Cedar Rapids, IA [Member] | Lease Terminations [Member] | Master Lease [Member] | Sears Holdings Corporation [Member]
Property Subject to or Available for Operating Lease [Line Items]
Gross leasable area	141,100
Notice	2018-04
Termination	2018-08
Citrus Heights, CA [Member] | Lease Terminations [Member] | Master Lease [Member] | Sears Holdings Corporation [Member]
Property Subject to or Available for Operating Lease [Line Items]
Gross leasable area	280,700
Notice	2018-04
Termination	2018-08
Gainesville, FL [Member] | Lease Terminations [Member] | Master Lease [Member] | Sears Holdings Corporation [Member]
Property Subject to or Available for Operating Lease [Line Items]
Gross leasable area	140,500
Notice	2018-04
Termination	2018-08
Announced Redevelopment	Q2 2018
Maplewood, MN [Member] | Lease Terminations [Member] | Master Lease [Member] | Sears Holdings Corporation [Member]
Property Subject to or Available for Operating Lease [Line Items]
Gross leasable area	168,500
Notice	2018-04
Termination	2018-08
Pensacola, FL [Member] | Lease Terminations [Member] | Master Lease [Member] | Sears Holdings Corporation [Member]
Property Subject to or Available for Operating Lease [Line Items]
Gross leasable area	212,300
Notice	2018-04
Termination	2018-08
Announced Redevelopment	Q2 2018
Rochester, NY [Member] | Lease Terminations [Member] | Master Lease [Member] | Sears Holdings Corporation [Member]
Property Subject to or Available for Operating Lease [Line Items]
Gross leasable area	128,500
Notice	2018-04
Termination	2018-08
Roseville, CA [Member] | Lease Terminations [Member] | Master Lease [Member] | Sears Holdings Corporation [Member]
Property Subject to or Available for Operating Lease [Line Items]
Gross leasable area	121,000
Notice	2018-04
Termination	2018-08
Announced Redevelopment	Q2 2017 / Q1 2018
San Antonio, TX [Member] | Lease Terminations [Member] | Master Lease [Member] | Sears Holdings Corporation [Member]
Property Subject to or Available for Operating Lease [Line Items]
Gross leasable area	187,800
Notice	2018-04
Termination	2018-08
Announced Redevelopment	Q4 2015
Warrenton, NJ [Member] | Lease Terminations [Member] | Master Lease [Member] | Sears Holdings Corporation [Member]
Property Subject to or Available for Operating Lease [Line Items]
Gross leasable area	113,900
Notice	2018-04
Termination	2018-08
Announced Redevelopment	Q1 2018
Madison, WI [Member]
Property Subject to or Available for Operating Lease [Line Items]
Gross leasable area	88,100
Notice	2018-06
Termination	2018-10
Announced Redevelopment	Q2 2016
Thousand Oaks, CA [Member]
Property Subject to or Available for Operating Lease [Line Items]
Gross leasable area	50,300
Notice	2018-06
Termination	2018-10
Announced Redevelopment	Q3 2015
Chesapeake, VA [Member]
Property Subject to or Available for Operating Lease [Line Items]
Gross leasable area	169,400
Notice	2018-06
Termination	2018-11
Clay, NY [Member]
Property Subject to or Available for Operating Lease [Line Items]
Gross leasable area	138,000
Notice	2018-06
Termination	2018-11
Havre, MT [Member]
Property Subject to or Available for Operating Lease [Line Items]
Gross leasable area	94,700
Notice	2018-06
Termination	2018-11
Newark, CA [Member]
Property Subject to or Available for Operating Lease [Line Items]
Gross leasable area	145,800
Notice	2018-06
Termination	2018-11
Oklahoma City, OK [Member]
Property Subject to or Available for Operating Lease [Line Items]
Gross leasable area	173,700
Notice	2018-06
Termination	2018-11
Announced Redevelopment	Q3 2017
Troy, MI [Member]
Property Subject to or Available for Operating Lease [Line Items]
Gross leasable area	271,300
Notice	2018-06
Termination	2018-11
Announced Redevelopment	Q3 2016
Virginia Beach, VA [Member]
Property Subject to or Available for Operating Lease [Line Items]
Gross leasable area	86,900
Notice	2018-06
Termination	2018-11
Announced Redevelopment	Q3 2015