REAL ESTATE PROPERTIES - Summary, Acquisitions, Dispositions (Details)		12 Months Ended
		Dec. 31, 2023 USD ($) ft² a	Dec. 31, 2022 USD ($) ft² a Integer shares	Dec. 31, 2021 USD ($) ft² a
Real Estate Companies Disclosures [Abstract]
Land		$ 814,364,000	$ 730,445,000
Buildings and building improvements		3,336,615,000	3,012,319,000
Tenant and other improvements		684,573,000	633,817,000
Right-of-Use Assets - Ground Leases (operating)	[1]	17,996,000	19,391,000
Development and value-add properties	[2]	639,647,000	538,449,000
Total real estate properties, gross		5,493,195,000	4,934,421,000
Less accumulated depreciation		1,273,723,000	1,150,814,000
Real estate investment property, Net		4,219,472,000	3,783,607,000
Asset Acquisition [Abstract]
Debt assumed in the purchase of real estate		$ 0	$ 60,000,000	$ 0
World Houston 23
Disposal Group, Not Discontinued Operation, Disposal Disclosures [Abstract]
Size (square feet) | ft²		125,000
Date Sold		Mar. 31, 2023
Disposal Group, Including Discontinued Operation, Consideration		$ 9,327,000
Basis		4,518,000
Recognized Gain		$ 4,809,000
Ettie Business Center
Disposal Group, Not Discontinued Operation, Disposal Disclosures [Abstract]
Size (square feet) | ft²		29,000
Date Sold		Nov. 20, 2023
Disposal Group, Including Discontinued Operation, Consideration		$ 11,638,000
Basis		8,845,000
Recognized Gain		$ 2,793,000
Los Angeles Corporate Center [Member]
Disposal Group, Not Discontinued Operation, Disposal Disclosures [Abstract]
Size (square feet) | ft²		77,000
Date Sold		Dec. 29, 2023
Disposal Group, Including Discontinued Operation, Consideration		$ 16,006,000
Basis		5,643,000
Recognized Gain		$ 10,363,000
Metro Business Park [Member]
Disposal Group, Not Discontinued Operation, Disposal Disclosures [Abstract]
Size (square feet) | ft²			189,000
Date Sold			Jan. 06, 2022
Disposal Group, Including Discontinued Operation, Consideration			$ 32,851,000
Basis			5,880,000
Recognized Gain			26,971,000
Cypress Creek Business Park [Member]
Real Estate Companies Disclosures [Abstract]
Right-of-Use Assets - Ground Leases (operating)			$ 1,745,000
Disposal Group, Not Discontinued Operation, Disposal Disclosures [Abstract]
Size (square feet) | ft²	[3]		56,000
Date Sold	[3]		Mar. 31, 2022
Disposal Group, Including Discontinued Operation, Consideration	[3]		$ 5,282,000
Basis	[3]		1,901,000
Recognized Gain	[3]		3,381,000
Operating Lease, Liability			$ 1,745,000
World Houston 15 East
Disposal Group, Not Discontinued Operation, Disposal Disclosures [Abstract]
Size (square feet) | ft²			42,000
Date Sold			May 11, 2022
Disposal Group, Including Discontinued Operation, Consideration			$ 12,873,000
Basis			2,226,000
Recognized Gain			$ 10,647,000
Jetport Commerce Park [Member]
Disposal Group, Not Discontinued Operation, Disposal Disclosures [Abstract]
Size (square feet) | ft²				284,000
Date Sold				Nov. 09, 2021
Disposal Group, Including Discontinued Operation, Consideration				$ 44,260,000
Basis				5,401,000
Recognized Gain				$ 38,859,000
2023 dispositions
Disposal Group, Not Discontinued Operation, Disposal Disclosures [Abstract]
Size (square feet) | ft²		231,000
Disposal Group, Including Discontinued Operation, Consideration		$ 36,971,000
Basis		19,006,000
Recognized Gain		$ 17,965,000
2022 Dispositions
Disposal Group, Not Discontinued Operation, Disposal Disclosures [Abstract]
Size (square feet) | ft²			287,000
Disposal Group, Including Discontinued Operation, Consideration			$ 51,006,000
Basis			10,007,000
Recognized Gain			$ 40,999,000
2023 land dispositions
Real Estate Properties
Acres of real estate investment property | ft²		11.9
Disposal Group, Not Discontinued Operation, Disposal Disclosures [Abstract]
Disposal Group, Including Discontinued Operation, Consideration		$ 4,750,000
Recognized Gain		$ 446,000
Craig Corporate Center
Asset Acquisition [Abstract]
Size (square feet) | ft²	[4]	156,000
Date acquired	[4]	Apr. 18, 2023
Costs	[4],[5]	$ 34,365,000
Blue Diamond Business Park
Asset Acquisition [Abstract]
Size (square feet) | ft²	[4]	254,000
Date acquired	[4]	Sep. 05, 2023
Costs	[4],[5]	$ 52,973,000
McKinney Logistics Center
Asset Acquisition [Abstract]
Size (square feet) | ft²	[4]	193,000
Date acquired	[4]	Oct. 02, 2023
Costs	[4],[5]	$ 25,739,000
Park at Myatt
Asset Acquisition [Abstract]
Size (square feet) | ft²	[4]	171,000
Date acquired	[4]	Nov. 03, 2023
Costs	[4],[5]	$ 30,793,000
Pelzer Point Commerce Center I
Asset Acquisition [Abstract]
Size (square feet) | ft²	[4]	213,000
Date acquired	[4]	Dec. 21, 2023
Costs	[4],[5]	$ 21,246,000
Cebrian Distribution Center and Reed Distribution Center
Asset Acquisition [Abstract]
Size (square feet) | ft²	[4],[6]		329,000
Date acquired	[4],[6]		Jun. 01, 2022
Costs	[4],[5],[6]		$ 49,726,000
6th Street Bus Cntr, Benicia Distrib Cntr 1-5, Ettie Bus Cntr, Laura Alice Bus Cntr, Preston Distrb Cntr, Sinclair Distrib Cntr, Transit Distrb Cntr and Whipple Bus Cntr
Asset Acquisition [Abstract]
Size (square feet) | ft²	[4],[6]		1,377,000
Date acquired	[4],[6]		Jun. 01, 2022
Costs	[4],[5],[6]		$ 309,404,000
Cypress Preserve 1 & 2
Asset Acquisition [Abstract]
Size (square feet) | ft²	[7]		516,000
Date acquired	[7]		Mar. 28, 2022
Costs	[5],[7]		$ 54,462,000
Zephyr Distribution Center
Asset Acquisition [Abstract]
Size (square feet) | ft²	[7]		82,000
Date acquired	[7]		Apr. 08, 2022
Costs	[5],[7]		$ 29,017,000
Mesa Gateway Commerce Center
Asset Acquisition [Abstract]
Size (square feet) | ft²	[7]		147,000
Date acquired	[7]		Apr. 15, 2022
Costs	[5],[7]		$ 18,315,000
Access Point 3
Asset Acquisition [Abstract]
Size (square feet) | ft²	[7]		299,000
Date acquired	[7]		Jul. 12, 2022
Costs	[5],[7]		$ 21,127,000
Southpark Distribution Center 2
Asset Acquisition [Abstract]
Size (square feet) | ft²	[4]			79,000
Date acquired	[4]			Jun. 10, 2021
Costs	[4],[5]			$ 9,177,000
DFW Global Logistics Centre
Asset Acquisition [Abstract]
Size (square feet) | ft²	[4]			611,000
Date acquired	[4]			Aug. 26, 2021
Costs	[4],[5]			$ 89,829,000
Progress Center 3
Asset Acquisition [Abstract]
Size (square feet) | ft²	[4]			50,000
Date acquired	[4]			Sep. 23, 2021
Costs	[4],[5]			$ 5,000,000
Texas Avenue Land
Asset Acquisition [Abstract]
Size (square feet) | ft²	[4]			20,000
Date acquired	[4]			Oct. 15, 2021
Costs	[4],[5]			$ 4,143,000
Access Point 1
Asset Acquisition [Abstract]
Size (square feet) | ft²	[7]			156,000
Date acquired	[7]			Jan. 15, 2021
Costs	[5],[7]			$ 10,501,000
Northpoint 200 [Member]
Asset Acquisition [Abstract]
Size (square feet) | ft²	[7]			79,000
Date acquired	[7]			Jan. 21, 2021
Costs	[5],[7]			$ 6,516,000
Access Point 2
Asset Acquisition [Abstract]
Size (square feet) | ft²	[7]			159,000
Date acquired	[7]			May 19, 2021
Costs	[5],[7]			$ 10,743,000
Cherokee 75 Business Center 2
Asset Acquisition [Abstract]
Size (square feet) | ft²	[7]			105,000
Date acquired	[7]			Jun. 17, 2021
Costs	[5],[7]			$ 8,837,000
Siempre Viva 3-6
Asset Acquisition [Abstract]
Size (square feet) | ft²	[7]			547,000
Date acquired	[7]			Dec. 01, 2021
Costs	[5],[7]			$ 134,479,000
Tulloch corporation
Asset Acquisition [Abstract]
Number of land parcels acquired | Integer			2
Debt assumed in the purchase of real estate			$ 60,000,000
Noncash or Part Noncash Acquisition, Noncash Financial or Equity Instrument Consideration, Shares Issued | shares			1,868,809
Fair value of loans assumed, asset acquisition			$ 60,000,000
Other Significant Noncash Transaction, Fair Value of Consideration Given, Common shares issued			$ 303,756,000
2023 operating property acquisitions
Asset Acquisition [Abstract]
Size (square feet) | ft²	[4]	987,000
Costs	[4],[5]	$ 165,116,000
2023 value-add acquisitions
Asset Acquisition [Abstract]
Size (square feet) | ft²	[7]	0
Costs	[5],[7]	$ 0
2023 acquisitions
Asset Acquisition [Abstract]
Size (square feet) | ft²	[8]	987,000
Costs	[5],[8]	$ 165,116,000
2022 operating property acquisitions
Asset Acquisition [Abstract]
Size (square feet) | ft²	[4]		1,706,000
Costs	[4],[5]		$ 359,130,000
2022 value-add acquisitions
Asset Acquisition [Abstract]
Size (square feet) | ft²	[7]		1,044,000
Costs	[5],[7]		$ 122,921,000
2022 acquisitions
Asset Acquisition [Abstract]
Size (square feet) | ft²	[8]		2,750,000
Costs	[5],[8]		$ 482,051,000
2021 operating property acquisitions
Asset Acquisition [Abstract]
Size (square feet) | ft²	[4]			760,000
Costs	[4],[5]			$ 108,149,000
2021 value-add acquisitions
Asset Acquisition [Abstract]
Size (square feet) | ft²	[7]			1,046,000
Costs	[5],[7]			$ 171,076,000
2021 acquisitions
Asset Acquisition [Abstract]
Size (square feet) | ft²	[8]			1,806,000
Costs	[5],[8]			$ 279,225,000
Development land
Real Estate Properties
Acres of real estate investment property | a		328.3	456.3	365.8
Asset Acquisition [Abstract]
Costs		$ 70,664,000	$ 123,717,000	$ 41,065,000

[1] See Ground Leases discussion below for information regarding the Company’s right of use assets for ground leases.

[2] Value-add properties are defined in Note 1(e).

[3] Cypress Creek Business Park is located on a ground lease. In conjunction with the sale of the property, the Company fully amortized the associated right-of-use asset and liability of $1,745,000.

[4] Operating properties are defined as stabilized real estate properties (land including buildings and improvements) in the Company’s operating portfolio; included in Real estate properties on the Consolidated Balance Sheets

[5] Cost is calculated in accordance with FASB ASC 805, Business Combinations, and represents the sum of the purchase price, closing costs and capitalized acquisition costs.

[6] The Company acquired these operating properties along with two land parcels, also in Sacramento, CA and San Francisco, CA, in connection with its acquisition of Tulloch Corporation in June 2022. Size and cost are presented on an aggregate basis for the properties located in Sacramento, CA and San Francisco, CA, respectively. In consideration for this acquisition, the Company assumed a $60,000,000 loan and issued 1,868,809 shares of the Company’s common stock. The acquisition date fair value of the loan assumed was $60,000,000, and the acquisition date fair value of the common shares, which was based on the closing share price on the acquisition date, was $303,756,000.

[7] Value-add properties are defined in Note 1(e).

[8] Excludes acquired development land as detailed below.