REAL ESTATE AND RELATED LEASE INTANGIBLES, NET - Schedule of Real Estate Properties Acquired (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014
Business Acquisition [Line Items]
Purchase Price	$ 166,763	$ 126,997
O'Fallon, Illinois [Member]
Business Acquisition [Line Items]
Purchase Price		$ 8,000
Ownership interest (percent)		100.00%
Jacksonville, NC
Business Acquisition [Line Items]
Purchase Price	$ 7,877
Ownership interest (percent)	100.00%
Iberia, MO
Business Acquisition [Line Items]
Purchase Price	$ 1,328
Ownership interest (percent)	100.00%
Isle, MN
Business Acquisition [Line Items]
Purchase Price	$ 1,078
Ownership interest (percent)	100.00%
Pine Island, MN
Business Acquisition [Line Items]
Purchase Price	$ 1,142
Ownership interest (percent)	100.00%
Kings Mountain, NC
Business Acquisition [Line Items]
Purchase Price	$ 21,241
Ownership interest (percent)	100.00%
Village of Menomonee Falls, WI
Business Acquisition [Line Items]
Purchase Price	$ 17,050
Ownership interest (percent)	100.00%
Rockland, MA
Business Acquisition [Line Items]
Purchase Price	$ 7,316
Ownership interest (percent)	100.00%
Crawfordsville, IA
Business Acquisition [Line Items]
Purchase Price	$ 6,000
Ownership interest (percent)	100.00%
Boardman Township, OH
Business Acquisition [Line Items]
Purchase Price	$ 5,400
Ownership interest (percent)	100.00%
Hilliard, OH
Business Acquisition [Line Items]
Purchase Price	$ 6,384
Ownership interest (percent)	100.00%
Weathersfield Township, OH
Business Acquisition [Line Items]
Purchase Price	$ 5,200
Ownership interest (percent)	100.00%
Rotterdam, NY
Business Acquisition [Line Items]
Purchase Price	$ 12,000
Ownership interest (percent)	100.00%
Wheaton, MO
Business Acquisition [Line Items]
Purchase Price	$ 970
Ownership interest (percent)	100.00%
Paynesville, MN
Business Acquisition [Line Items]
Purchase Price	$ 1,254
Ownership interest (percent)	100.00%
Loveland, CO
Business Acquisition [Line Items]
Purchase Price	$ 5,600
Ownership interest (percent)	100.00%
Battle Lake, MN
Business Acquisition [Line Items]
Purchase Price	$ 1,098
Ownership interest (percent)	100.00%
Yorktown, TX
Business Acquisition [Line Items]
Purchase Price	$ 1,207
Ownership interest (percent)	100.00%
St. Francis, MN
Business Acquisition [Line Items]
Purchase Price	$ 1,117
Ownership interest (percent)	100.00%
Red Oak, IA
Business Acquisition [Line Items]
Purchase Price	$ 1,185
Ownership interest (percent)	100.00%
Zapata, TX
Business Acquisition [Line Items]
Purchase Price	$ 1,150
Ownership interest (percent)	100.00%
Aurora, MN
Business Acquisition [Line Items]
Purchase Price	$ 952
Ownership interest (percent)	100.00%
Canyon Lake, TX
Business Acquisition [Line Items]
Purchase Price	$ 1,377
Ownership interest (percent)	100.00%
Wheeler, TX
Business Acquisition [Line Items]
Purchase Price	$ 1,075
Ownership interest (percent)	100.00%
Grand Rapids, MI
Business Acquisition [Line Items]
Purchase Price	$ 9,300
Ownership interest (percent)	97.00%
Grand Rapids, MI
Business Acquisition [Line Items]
Purchase Price	$ 6,300
Ownership interest (percent)	97.00%
Bridgeport, IL
Business Acquisition [Line Items]
Purchase Price	$ 1,186
Ownership interest (percent)	100.00%
Peoria, IL
Business Acquisition [Line Items]
Purchase Price	$ 1,226
Ownership interest (percent)	100.00%
Pleasanton, TX
Business Acquisition [Line Items]
Purchase Price	$ 1,316
Ownership interest (percent)	100.00%
Wayne, NJ
Business Acquisition [Line Items]
Purchase Price	$ 9,700
Ownership interest (percent)	100.00%
Warren, MN
Business Acquisition [Line Items]
Purchase Price	$ 1,055
Ownership interest (percent)	100.00%
Tremont, IL
Business Acquisition [Line Items]
Purchase Price	$ 1,150
Ownership interest (percent)	100.00%
Ponce, Puerto Rico
Business Acquisition [Line Items]
Purchase Price	$ 8,900
Ownership interest (percent)	100.00%
Effingham County, IL
Business Acquisition [Line Items]
Purchase Price	$ 1,195
Ownership interest (percent)	100.00%
Lebanon, MI
Business Acquisition [Line Items]
Purchase Price	$ 1,200
Ownership interest (percent)	100.00%
Minot, ND
Business Acquisition [Line Items]
Purchase Price	$ 6,644
Ownership interest (percent)	100.00%
Floresville, TX
Business Acquisition [Line Items]
Purchase Price	$ 1,251
Ownership interest (percent)	100.00%
Kerrville, TX
Business Acquisition [Line Items]
Purchase Price	$ 1,174
Ownership interest (percent)	97.00%
De Soto, IL
Business Acquisition [Line Items]
Purchase Price	$ 1,066
Ownership interest (percent)	97.00%
Biscoe, NC
Business Acquisition [Line Items]
Purchase Price	$ 1,216
Ownership interest (percent)	100.00%
Moultrie, GA
Business Acquisition [Line Items]
Purchase Price	$ 1,305
Ownership interest (percent)	100.00%
Rose Hill, NC
Business Acquisition [Line Items]
Purchase Price	$ 1,420
Ownership interest (percent)	100.00%
Rockingham, NC
Business Acquisition [Line Items]
Purchase Price	$ 1,158
Ownership interest (percent)	100.00%
El Centro, CA
Business Acquisition [Line Items]
Purchase Price		$ 4,277
Ownership interest (percent)		100.00%
Richmond, VA
Business Acquisition [Line Items]
Purchase Price		$ 19,850
Ownership interest (percent)		77.50%
Conyers, GA
Business Acquisition [Line Items]
Purchase Price		$ 32,530
Ownership interest (percent)		100.00%
St. Paul, MN
Business Acquisition [Line Items]
Purchase Price		$ 62,340
Ownership interest (percent)		97.00%