v3.8.0.1

Acquisitions - Acquisitions Closed - (Detail) $ in Thousands																																																																					12 Months Ended
	Dec. 29, 2017 USD ($) Property	Dec. 28, 2017 USD ($) Property	Dec. 27, 2017 USD ($) Property	Dec. 22, 2017 USD ($) Property	Dec. 18, 2017 USD ($) Property	Dec. 14, 2017 USD ($) Property	Dec. 08, 2017 USD ($) Property	Dec. 07, 2017 USD ($) Property	Nov. 01, 2017 USD ($) Property	Oct. 13, 2017 USD ($) Property	Sep. 29, 2017 USD ($) Property	Sep. 13, 2017 USD ($) Property	Aug. 31, 2017 USD ($) Property	Aug. 04, 2017 USD ($) Property	Jul. 07, 2017 USD ($) Property	Jun. 30, 2017 USD ($) Property	Jun. 15, 2017 USD ($) Property	Jun. 02, 2017 USD ($) Property	Apr. 28, 2017 USD ($) Property	Mar. 01, 2017 USD ($) Property	Jan. 18, 2017 USD ($) Property	Dec. 30, 2016 USD ($) Property	Dec. 23, 2016 USD ($) Property	Dec. 19, 2016 USD ($) Property	Nov. 29, 2016 USD ($) Property	Nov. 21, 2016 USD ($) Property	Nov. 10, 2016 USD ($) Property	Oct. 03, 2016 USD ($) Property	Sep. 29, 2016 USD ($) Property	Sep. 14, 2016 USD ($) Property	Aug. 12, 2016 USD ($) Property	Jul. 15, 2016 USD ($) Property	Jun. 30, 2016 USD ($) Property	May 25, 2016 USD ($)	May 20, 2016 USD ($) Property	May 12, 2016 USD ($) Property	May 09, 2016 USD ($) Property	Apr. 25, 2016 USD ($) Property	Apr. 07, 2016 USD ($) Property	Mar. 24, 2016 USD ($) Property	Feb. 01, 2016 USD ($) Property	Jan. 25, 2016 USD ($) Property	Dec. 30, 2015 USD ($) Property	Dec. 17, 2015 USD ($) Property	Dec. 15, 2015 USD ($) Property	Dec. 08, 2015 USD ($) Property	Nov. 23, 2015 USD ($) Property	Oct. 23, 2015 USD ($) Property	Oct. 05, 2015 USD ($) Property	Sep. 30, 2015 USD ($) Property	Sep. 28, 2015 USD ($) Property	Sep. 25, 2015 USD ($) Property	Sep. 15, 2015 USD ($) Property	Jul. 17, 2015 USD ($)	Jun. 29, 2015 USD ($) Property	Jun. 26, 2015 USD ($) Property	Jun. 24, 2015 USD ($) Property	Jun. 19, 2015 USD ($) Property	May 15, 2015 USD ($) Property	Apr. 02, 2015 USD ($) Property	Mar. 31, 2015 USD ($) Property	Mar. 26, 2015 USD ($) Property	Mar. 24, 2015 USD ($) Property	Mar. 12, 2015 USD ($) Property	Mar. 09, 2015 USD ($) Property	Feb. 12, 2015 USD ($) Property	Jan. 09, 2015 USD ($) Property	Jan. 06, 2015 USD ($) Property	Dec. 31, 2017 USD ($) Property	Dec. 31, 2016 USD ($) Property	Dec. 31, 2015 USD ($) Property
Business Acquisition [Line Items]
Number of Properties | Property																																																																					124	88	116
Real Estate Acquisition Price																																																																					$ 683,644	$ 518,812	$ 550,128
Retail
Business Acquisition [Line Items]
Tenant Type	Retail		Retail									Retail					Retail		Retail	Retail	Retail					Retail		Retail	Retail				Retail		Retail		Retail				Retail	Retail	Retail	Retail		Retail			Retail	Retail		Retail				Retail		Retail						Retail	Retail
Number of Properties | Property	9		1									5					2		25	9	1					2		6	24				7		19		5				1	3	3	15		8			36	1		3				1		10						5	1
Real Estate Acquisition Price	$ 28,224		$ 1,446									$ 4,994					$ 2,700		$ 48,898	$ 87,196	$ 2,520					$ 7,597		$ 6,872	$ 82,338				$ 28,477		$ 36,843		$ 42,390				$ 27,000	$ 13,376	$ 11,913	$ 62,468		$ 18,191			$ 83,032	$ 4,030		$ 11,195				$ 1,558		$ 19,663						$ 14,542	$ 3,563
Healthcare
Business Acquisition [Line Items]
Tenant Type	Healthcare							Healthcare		Healthcare			Healthcare	Healthcare		Healthcare		Healthcare														Healthcare		Healthcare					Healthcare								Healthcare												Healthcare									Healthcare
Number of Properties | Property	6							1		1			3	3		7		2														2							2								1												5									1
Real Estate Acquisition Price	$ 19,868							$ 5,095		$ 10,000			$ 16,700	$ 11,732		$ 25,989		$ 13,300														$ 26,700		$ 5,624					$ 17,115								$ 56,600												$ 17,125									$ 4,400
Industrial
Business Acquisition [Line Items]
Tenant Type		Industrial		Industrial							Industrial		Industrial			Industrial						Industrial		Industrial																Industrial					Industrial			Industrial			Industrial		Industrial			Industrial				Industrial	Industrial	Industrial	Industrial				Industrial
Number of Properties | Property		1		2							1		2			2						1		1																1					1			2			2		1			5				1	2	1	1				1
Real Estate Acquisition Price		$ 28,450		$ 19,000							$ 57,372		$ 6,148			$ 12,250						$ 15,487		$ 23,050																$ 15,650					$ 1,500			$ 51,600			$ 10,193		$ 12,720			$ 41,169				$ 10,764	$ 9,751	$ 21,750	$ 11,354				$ 4,300
Office
Business Acquisition [Line Items]
Tenant Type						Office		Office							Office							Office	Office		Office		Office			Office						Office		Office																	Office		Office									Office
Number of Properties | Property						1		2							1							1	1		4		1			1						1		2																	1		2									2
Real Estate Acquisition Price						$ 24,500		$ 19,295							$ 32,210							$ 15,550	$ 43,517		$ 15,177		$ 10,550			$ 14,000						$ 4,500		$ 54,600																	$ 15,600		$ 33,300									$ 8,796
Industrial, Retail
Business Acquisition [Line Items]
Tenant Type											Industrial, Retail
Number of Properties | Property											7
Real Estate Acquisition Price											$ 30,012
Other
Business Acquisition [Line Items]
Tenant Type					Other				Other																						Other
Number of Properties | Property					1				4																						3
Real Estate Acquisition Price					$ 22,585				$ 15,693																						$ 12,399
Healthcare
Business Acquisition [Line Items]
Tenant Type								Healthcare
Number of Properties | Property								1
Real Estate Acquisition Price								$ 2,678
Industrial, Office
Business Acquisition [Line Items]
Tenant Type							Industrial, Office
Number of Properties | Property							3
Real Estate Acquisition Price							$ 74,200
Industrial
Business Acquisition [Line Items]
Tenant Type				Industrial
Number of Properties | Property				1
Real Estate Acquisition Price				$ 21,037
Retail
Business Acquisition [Line Items]
Tenant Type	Retail																																																									Retail
Number of Properties | Property	20																																																									1
Real Estate Acquisition Price	$ 39,552																																																									$ 2,259
Retail, Industrial
Business Acquisition [Line Items]
Tenant Type																																																												Retail, Industrial
Number of Properties | Property																																																												3
Real Estate Acquisition Price																																																												$ 6,090
Land
Business Acquisition [Line Items]
Tenant Type																																																						Land
Real Estate Acquisition Price																																																						$ 702

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- Definition

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+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 13
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=98514028&loc=d3e3213-108585

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