Leases - Summary of Recapture Rights Exercised by the Company (Detail)	3 Months Ended
	Mar. 31, 2018
Property Subject to or Available for Operating Lease [Line Items]
Recapture Type, Percentage	100.00%
Asheville, NC [Member]
Property Subject to or Available for Operating Lease [Line Items]
Recapture Type, Percentage	100.00%
Notice Date(s)	2018-03
Temecula, CA [Member]
Property Subject to or Available for Operating Lease [Line Items]
Recapture Type	Partial
Notice Date(s)	2017-06
Cockeysville, MD [Member]
Property Subject to or Available for Operating Lease [Line Items]
Recapture Type	Partial
Notice Date(s)	2017-03
Chicago, IL [Member]
Property Subject to or Available for Operating Lease [Line Items]
Recapture Type, Percentage	100.00%
Notice Date(s)	2018-03
Ft. Wayne, IN Property 1 [Member]
Property Subject to or Available for Operating Lease [Line Items]
Recapture Type	Out parcel
Notice Date	September 2017 / July 2016
Roseville, CA [Member]
Property Subject to or Available for Operating Lease [Line Items]
Recapture Type	Auto center
Notice Date(s)	2017-06
North Miami, FL [Member]
Property Subject to or Available for Operating Lease [Line Items]
Recapture Type, Percentage	100.00%
Notice Date(s)	2017-03
Clearwater, FL [Member]
Property Subject to or Available for Operating Lease [Line Items]
Recapture Type, Percentage	100.00%
Notice Date(s)	2018-03
St. Clair Shores, MI [Member]
Property Subject to or Available for Operating Lease [Line Items]
Recapture Type, Percentage	100.00%
Notice Date(s)	2017-09
North Riverside, IL [Member]
Property Subject to or Available for Operating Lease [Line Items]
Recapture Type	Partial
Notice Date(s)	2017-06
Olean, NY [Member]
Property Subject to or Available for Operating Lease [Line Items]
Recapture Type	Partial
Notice Date(s)	2017-03
El Cajon, CA [Member]
Property Subject to or Available for Operating Lease [Line Items]
Recapture Type, Percentage	100.00%
Notice Date(s)	2018-03
Austin TX [Member]
Property Subject to or Available for Operating Lease [Line Items]
Recapture Type, Percentage	100.00%
Notice Date	December 2017 / September 2017
Watchung, NJ [Member]
Property Subject to or Available for Operating Lease [Line Items]
Recapture Type, Percentage	100.00%
Notice Date(s)	2017-06
Carson, CA [Member]
Property Subject to or Available for Operating Lease [Line Items]
Recapture Type, Percentage	100.00%
Notice Date	April 2017 / December 2016
Fairfield, CA [Member]
Property Subject to or Available for Operating Lease [Line Items]
Recapture Type, Percentage	100.00%
Notice Date	March 2018 / December 2017
Redmond WA [Member]
Property Subject to or Available for Operating Lease [Line Items]
Recapture Type, Percentage	100.00%
Notice Date	March 2018 / September 2017
Canton, OH [Member]
Property Subject to or Available for Operating Lease [Line Items]
Recapture Type	Partial
Notice Date(s)	2017-06
Saugus, MA [Member]
Property Subject to or Available for Operating Lease [Line Items]
Recapture Type	Partial
Notice Date(s)	2016-12
Oklahoma City, OK [Member]
Property Subject to or Available for Operating Lease [Line Items]
Recapture Type	Out parcel
Notice Date(s)	2018-03
Dayton, OH [Member]
Property Subject to or Available for Operating Lease [Line Items]
Recapture Type	Auto center
Notice Date(s)	2017-06
Guaynabo, PR [Member]
Property Subject to or Available for Operating Lease [Line Items]
Recapture Type	Partial
Notice Date(s)	2016-12
Plantation, FL [Member]
Property Subject to or Available for Operating Lease [Line Items]
Recapture Type, Percentage	100.00%
Notice Date	March 2018 / December 2017
Santa Cruz, CA [Member]
Property Subject to or Available for Operating Lease [Line Items]
Recapture Type	Partial
Notice Date(s)	2016-12
San Diego, CA [Member]
Property Subject to or Available for Operating Lease [Line Items]
Recapture Type, Percentage	100.00%
Notice Date(s)	2017-04
Santa Monica, CA [Member]
Property Subject to or Available for Operating Lease [Line Items]
Recapture Type, Percentage	100.00%
Notice Date(s)	2016-12
Reno, NV [Member]
Property Subject to or Available for Operating Lease [Line Items]
Recapture Type, Percentage	100.00%
Notice Date(s)	2018-03
Aventura, FL [Member]
Property Subject to or Available for Operating Lease [Line Items]
Recapture Type, Percentage	100.00%
Notice Date(s)	2017-04
Roseville, MI [Member]
Property Subject to or Available for Operating Lease [Line Items]
Recapture Type	Partial
Notice Date(s)	2016-11
Tucson, AZ [Member]
Property Subject to or Available for Operating Lease [Line Items]
Recapture Type, Percentage	100.00%
Notice Date(s)	2018-03
Hialeah, FL [Member]
Property Subject to or Available for Operating Lease [Line Items]
Recapture Type, Percentage	100.00%
Notice Date(s)	2017-04
Troy, MI [Member]
Property Subject to or Available for Operating Lease [Line Items]
Recapture Type	Partial
Notice Date(s)	2016-11
Anchorage, AK [Member]
Property Subject to or Available for Operating Lease [Line Items]
Recapture Type, Percentage	100.00%
Notice Date(s)	2017-12
Charleston, SC [Member]
Property Subject to or Available for Operating Lease [Line Items]
Recapture Type, Percentage	100.00%
Notice Date	April 2017 / October 2016
Boca Raton, FL [Member]
Property Subject to or Available for Operating Lease [Line Items]
Recapture Type, Percentage	100.00%
Notice Date(s)	2017-12
Rehoboth Beach, DE [Member]
Property Subject to or Available for Operating Lease [Line Items]
Recapture Type	Partial
Notice Date(s)	2016-10
Westminster, CA [Member]
Property Subject to or Available for Operating Lease [Line Items]
Recapture Type, Percentage	100.00%
Notice Date(s)	2017-12
Valley View, TX [Member]
Property Subject to or Available for Operating Lease [Line Items]
Recapture Type, Percentage	100.00%
Notice Date(s)	2017-04
St. Petersburg, FL [Member]
Property Subject to or Available for Operating Lease [Line Items]
Recapture Type, Percentage	100.00%
Notice Date(s)	2016-10
Hicksville, NY [Member]
Property Subject to or Available for Operating Lease [Line Items]
Recapture Type, Percentage	100.00%
Notice Date(s)	2017-12
Warwick, RI [Member]
Property Subject to or Available for Operating Lease [Line Items]
Recapture Type	Auto center
Notice Date(s)	2016-10
Orland Park, IL [Member]
Property Subject to or Available for Operating Lease [Line Items]
Recapture Type, Percentage	100.00%
Notice Date(s)	2017-12
West Hartford, CT [Member]
Property Subject to or Available for Operating Lease [Line Items]
Recapture Type, Percentage	100.00%
Notice Date(s)	2016-10
Florissant, MO [Member]
Property Subject to or Available for Operating Lease [Line Items]
Recapture Type	Out parcel
Notice Date(s)	2017-12
North Hollywood, CA [Member]
Property Subject to or Available for Operating Lease [Line Items]
Recapture Type	Partial
Notice Date(s)	2016-07
Salem, NH [Member]
Property Subject to or Available for Operating Lease [Line Items]
Recapture Type	Out parcel
Notice Date(s)	2017-12
Anderson, SC [Member]
Property Subject to or Available for Operating Lease [Line Items]
Recapture Type, Percentage	100.00%
Notice Date	April 2017 / July 2016
Las Vegas, NV [Member]
Property Subject to or Available for Operating Lease [Line Items]
Recapture Type	Partial
Notice Date(s)	2017-12
Yorktown Heights [Member]
Property Subject to or Available for Operating Lease [Line Items]
Recapture Type	Partial
Notice Date(s)	2017-12
Madison, WI [Member]
Property Subject to or Available for Operating Lease [Line Items]
Recapture Type	Partial
Notice Date(s)	2016-07
Orlando, FL [Member]
Property Subject to or Available for Operating Lease [Line Items]
Recapture Type, Percentage	100.00%
Notice Date(s)	2016-07
West Jordan, UT [Member]
Property Subject to or Available for Operating Lease [Line Items]
Recapture Type	Partial + auto center
Notice Date(s)	2016-07
North Little Rock, AR [Member]
Property Subject to or Available for Operating Lease [Line Items]
Recapture Type	Auto Center
Notice Date(s)	2017-09
Albany, NY [Member]
Property Subject to or Available for Operating Lease [Line Items]
Recapture Type	Auto center
Notice Date(s)	2016-05
Bowie, MD [Member]
Property Subject to or Available for Operating Lease [Line Items]
Recapture Type	Auto center
Notice Date(s)	2016-05
Fairfax, VA [Member]
Property Subject to or Available for Operating Lease [Line Items]
Recapture Type	Partial + auto center
Notice Date(s)	2016-05
Hagerstown, MD [member]
Property Subject to or Available for Operating Lease [Line Items]
Recapture Type	Auto center
Notice Date(s)	2016-05
Wayne, NJ [Member]
Property Subject to or Available for Operating Lease [Line Items]
Recapture Type	Partial + auto center
Notice Date(s)	2016-05
San Antonio, TX [Member]
Property Subject to or Available for Operating Lease [Line Items]
Recapture Type	Auto center
Notice Date(s)	2016-03
Memphis, TN [Member]
Property Subject to or Available for Operating Lease [Line Items]
Recapture Type, Percentage	100.00%
Notice Date(s)	2015-12
Honolulu, HI [Member]
Property Subject to or Available for Operating Lease [Line Items]
Recapture Type, Percentage	100.00%
Notice Date(s)	2015-12
Braintree, MA [Member]
Property Subject to or Available for Operating Lease [Line Items]
Recapture Type, Percentage	100.00%
Notice Date(s)	2015-11